Device and method in radio communication system, and computer-readable storage medium

ABSTRACT

Provided in the present disclosure are a device and method in a radio communication system, and a computer-readable storage medium. The device comprises a processing circuit configured to: decode a group common physical downlink control channel (group common PDCCH) of a user equipment group comprising a target user equipment so as to acquire control information related to multi-user multiple input multiple output (MU-MIMO) transmission of a control channel; and decode a user equipment-specific physical downlink control channel (UE-specific PDCCH) of the target user equipment on the basis of the control information so as to acquire specific transmission control information related to the target user equipment, where the UE-specific PDCCH of the target user equipment and UE-specific PDCCH of the other user equipment are stacked on a same transmission resource for transmission. MU-MIMO transmission with respect to a downlink control channel is effectively implemented, thus increasing resource utilization rate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/754,748, filed Apr. 9, 2020, which is based on PCT filingPCT/CN2019/074664, filed Feb. 3, 2019, and claims priority to ChinesePatent Application No. 201810140997.9, filed on Feb. 11, 2018 with theChinese Patent Office, each of which is incorporated herein by referencein its entirety.

FIELD

The present disclosure relates to the field of wireless communications,in particular to a device and method in a wireless communication systemfor optimizing Multi-User Multiple Input Multiple Output (MU-MIMO)transmission, and a non-volatile computer readable storage medium.

BACKGROUND

As a next generation of radio access manner of Long Term Evolution(LTE), New Radio (NR) is radio access technology (RAT) different fromLTE. NR is an access technology capable of dealing with various usecases such as Enhanced mobile broadband (eMBB), Massive machine typecommunication (mMTC) and Ultra reliable and low latency communications(URLLC). NR is studied by taking technical construction corresponding toutilization scenarios, request conditions and configuration scenarios inthese use cases as a target. Detailed content of the scenarios andrequest conditions for NR is disclosed in non-patent document 1.

In an aspect, in the existing LTE (or referred to as 4G)/NR (or referredto as 5G) wireless communication system, “transparent” MU-MIMOtransmission for a downlink data channel (that is, physical downlinkshared channel PDSCH) has been supported. The so-called “transparent”MU-MIMO transmission refers to that target user equipment (UE) does notknow existence of other user equipment which is scheduled simultaneouslywith the target user equipment to perform MU-MIMO transmission. That is,the target UE does not know accurate interference on a layer where atarget data flow is located from a layer where a data flow of other userequipment is located, and thus a receiver of the target UE only tries todecode a target data flow and cannot efficiently process interferencebetween layers.

In the “transparent” MU-MIMO transmission, the user equipment does notknow interference conditions between multiple user equipment, thusinterference measurement among multiple user equipment cannot beachieved and interference among multiple user equipment cannot besuppressed or removed, resulting in reducing of throughput andreliability of the system to a certain degree.

In another aspect, in the existing 4G/5G communication system, MU-MIMOtransmission for a downlink control channel (physical downlink controlchannel, PDCCH) is not put forward. In the conventional technology, onlyUE-specific physical downlink control channel (UE-specific PDCCH) forcertain user equipment is transmitted for a certain transmissionresource, and the transmission resource cannot be shared between controlchannels of different user equipment by using a spatial domainprocessing capability of multiple antennas. That is, in the conventionaltechnology, UE-specific PDCCHs of different user equipment cannot besuperposed on the same transmission resource for transmission, resultingin reducing of utilization of the time-frequency resource.

CONVENTIONAL TECHNOLOGY DOCUMENT Non-Patent Document

Non-patent document 1: 3rd Generation Partnership Project; TechnicalSpecification

Group Radio Access Network; Study on Scenarios and Requirements for NextGeneration Access Technologies; (Release 14), 3GPP TR 38.913 V0.2.0(2016-02).

SUMMARY

A brief summary of embodiments of the present disclosure is given in thefollowing, so as to provide basic understanding on some aspects of thepresent disclosure. It should be understood that, the summary is not anexhaustive summary of the present disclosure. The summary is neitherintended to determine key or important parts of the present disclosure,nor intended to limit the scope of the present disclosure. An object ofthe summary is to provide some concepts in a simplified form, aspreamble of a detailed description later.

In view of the above problems, an object of at least one aspect of thepresent disclosure is to provide a device and a method in a wirelesscommunication system and a non-volatile computer readable storagemedium, which can efficiently achieve MU-MIMO transmission for adownlink control channel.

An object of another aspect of the present disclosure is to provide adevice and a method for a wireless communication system, and anon-volatile computer readable storage medium, so that target userequipment can indirectly acquire interferences from other user equipmentwhich is scheduled simultaneously with the target user equipment toperform MU-MIMO transmission for a downlink data channel, therebyimproving throughput and reliability of the system.

According to an aspect of the present disclosure, a device in a wirelesscommunication system, the device comprising processing circuitryconfigured to: decode a group common physical downlink control channel(group common PDCCH) for a group of user equipment including target userequipment to obtain control information related to Multi-User MultipleInput Multiple Output (MU-MIMO) transmission of control channel; anddecode, based on the control information, user specific physicaldownlink control channel (UE-specific PDCCH) of the target userequipment to obtain specific transmission control information for thetarget user equipment, where the UE-specific PDCCH of the target userequipment and UE-specific PDCCH of other user equipment in the group ofuser equipment are superposed on same transmission resource to betransmitted.

According to another aspect of the present disclosure, a device in awireless communication system is further provided. The device includesprocessing circuitry. The processing circuitry is configured to:generate a group common physical downlink control channel (group commonPDCCH) for a group of user equipment and user specific physical downlinkcontrol channel (UE-specific PDCCH) of each of the group of userequipment, the group common physical downlink control channel includingcontrol information related to Multi-User Multiple Input Multiple Output(MU-MIMO) transmission of control channel of all user equipment in thegroup of user equipment; control a base station to transmit the groupcommon physical downlink control channel to the group of user equipment;and control, based on the control information, the base station totransmit the UE-specific PDCCH of each of the group of user equipment onsame transmission resource.

According to another aspect of the present disclosure, a method in awireless communication system is further provided. The method includes:decoding a group common physical downlink control channel (group commonPDCCH) for a group of user equipment including target user equipment toobtain control information related to Multi-User Multiple Input MultipleOutput (MU-MIMO) transmission of control channel; and decoding, based onthe control information, user specific physical downlink control channel(UE-specific PDCCH) of the target user equipment to obtain specifictransmission control information for the target user equipment, wherethe UE-specific PDCCH of the target user equipment and UE-specific PDCCHof other user equipment in the group of user equipment are superposed onsame transmission resource to be transmitted.

According to another aspect of the present disclosure, a method in awireless communication system is further provided. The method includes:generating a group common physical downlink control channel (groupcommon PDCCH) for a group of user equipment and user specific physicaldownlink control channel (UE-specific PDCCH) of each of the group ofuser equipment, the group common physical downlink control channelincluding control information related to Multi-User Multiple InputMultiple Output (MU-MIMO) transmission of control channel of all userequipment in the group of user equipment; controlling a base station totransmit the group common physical downlink control channel to the groupof user equipment; and controlling, based on the control information,the base station to transmit the UE-specific PDCCH of each of the groupof user equipment on same transmission resource.

According to another aspect of the present disclosure, a device in awireless communication system is provided. The device includesprocessing circuitry. The processing circuitry is configured to:determine, according to control information, which is related toMulti-User Multiple Input Multiple Output (MU-MIMO) transmissionperformed by user equipment and other user equipment scheduledsimultaneously, from a base station, transmission related configurationof the other user equipment, where the control information includesinformation indirectly indicating the transmission related configurationof the other user equipment; and decode, based on the determinedtransmission related configuration of the other user equipment, signalstransmitted with the MU-MIMO transmission and received from the basestation to obtain a signal portion for the user equipment.

According to another aspect of the present disclosure, a device in awireless communication system is provided. The device includesprocessing circuitry. The processing circuitry is configured to: foreach of one or more user equipment in a group of user equipment whichare simultaneously scheduled to perform Multi-User Multiple InputMultiple Output (MU-MIMO) transmission, generate control informationrelated to the MU-MIMO transmission and control a base station totransmit the control information to this user equipment, where thecontrol information includes information indirectly indicatingtransmission related configuration of other user equipment than thisuser equipment in the group of user equipment; and control the basestation to simultaneously transmit signals to the group of userequipment on specific transmission resource.

According to another aspect of the present disclosure, a method in awireless communication system is further provided. The method includes:determining, according to control information, which is related toMulti-User Multiple Input Multiple Output (MU-MIMO) transmissionperformed by user equipment and other user equipment scheduledsimultaneously, from a base station, transmission related configurationof the other user equipment, where the control information includesinformation indirectly indicating the transmission related configurationof the other user equipment; and decoding, based on the determinedtransmission related configuration of the other user equipment, signalstransmitted with the MU-MIMO transmission and received from the basestation to obtain a signal portion for the user equipment.

According to another aspect of the present disclosure, a method in awireless communication system is further provided. The method includes:for each of one or more user equipment in a group of user equipmentwhich are simultaneously scheduled to perform Multi-User Multiple InputMultiple Output (MU-MIMO) transmission, generating control informationrelated to the MU-MIMO transmission and controlling a base station totransmit the control information to this user equipment, where thecontrol information includes information indirectly indicatingtransmission related configuration of other user equipment than thisuser equipment in the group of user equipment; and controlling the basestation to simultaneously transmit signals to the group of userequipment on specific transmission resource.

According to another aspect of the present disclosure, a non-volatilecomputer readable storage medium storing executable instructions isfurther provided. When the executable instructions are executed by aprocessor, the processor is caused to perform the method in the wirelesscommunication system or functions of the device in the wirelesscommunication system described above.

According other aspect of the present disclosure, a computer programcode and a computer program product for implementing the methodaccording to the present disclosure are further provided.

According to at least one aspect of embodiments of the presentdisclosure, the control information of MU-MIMO transmission for thecontrol channel of a group of user equipment is carried in the groupcommon physical downlink control channel, so that each user equipmentcan obtain transmission related configuration (for example DMRSconfiguration) of its UE-specific PDCCH by decoding the group commonphysical downlink control channel, and extracts its UE-specific PDCCHfrom the received superposed signal according to the transmissionrelated configuration, thereby efficiently implementing MU-MIMOtransmission for the downlink control channel, and improving resourceutilization.

According to at least another aspect of the present disclosure, for theMU-MIMO transmission of the downlink data channel, transmission relatedconfiguration of other user equipment scheduled simultaneously with thetarget UE is indirectly indicated to the target UE, so that the limitedphysical layer scheduling signaling can be effectively utilized and thusthe target UE can determine, suppress and/or remove interferences fromother user equipment according to the transmission relatedconfiguration, thereby decoding to obtain a target data flow for thetarget UE and improving the throughput and reliability of the system.

Other aspects of the embodiments of the present disclosure are given inthe following specification. Preferred embodiments for fully disclosingthe present disclosure are described in detail, and the preferredembodiments are not intended to limit the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood with reference to thedetailed description below given in conjunction the drawings. The sameor similar components are represented by the same or similar referencenumerals. The drawings together with the detailed description below areincluded in the specification and form a part of the specification, forillustrating preferred embodiments of the present disclosure andexplaining the principles and advantages of the present disclosure byexamples. In the drawings:

FIG. 1 is a schematic diagram of an example showing “transparent”MU-MIMO transmission;

FIG. 2 is a schematic diagram of an example showing “non-transparent”MU-MIMO transmission;

FIG. 3 is a block diagram of an example showing functional configurationof a device at a UE side according to a first embodiment of the presentdisclosure;

FIG. 4 is a block diagram of an example showing functional configurationof a device at a base station side according to a first embodiment ofthe present disclosure;

FIG. 5 is a block diagram of another example showing functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure;

FIG. 6 is a block diagram of another example showing functionalconfiguration of the device at the base station side according to thefirst embodiment of the present disclosure;

FIG. 7 is a flowchart showing signaling interaction process forimplementing a first schematic scheme according to the first embodimentof the present disclosure;

FIG. 8 is a schematic diagram of an example showing a mappingrelationship between CSI-RS resource or a CSI-RS port and a DMRS portaccording to the first embodiment of the present disclosure;

FIG. 9 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure;

FIG. 10 is a block diagram of an example showing specific functionalconfiguration of a determination unit in the device at the UE sideaccording to the first embodiment of the present disclosure;

FIG. 11 is a block diagram of an example showing specific functionalconfiguration of an interference measuring unit in the device at the UEside according to the first embodiment of the present disclosure;

FIG. 12 is a block diagram of another example showing the functionalconfiguration of the device at the base station side according to thefirst embodiment of the present disclosure;

FIG. 13 is a block diagram of an example showing specific functionalconfiguration of a control information generation unit in the device atthe base station side according to the first embodiment of the presentdisclosure;

FIG. 14 is a flowchart showing signaling interaction process forimplementing a second schematic solution according to the firstembodiment of the present disclosure;

FIG. 15 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure;

FIG. 16 is a block diagram of another example showing the functionalconfiguration of the device at the base station side according to thefirst embodiment of the present disclosure;

FIG. 17 is a flowchart showing signaling interaction process forimplementing a third schematic scheme according to the first embodimentof the present disclosure;

FIG. 18 is a schematic diagram of an example showing mapping patterns ofDMRS ports 7-10 on resource elements (RE);

FIG. 19 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure;

FIG. 20 is a block diagram of another example showing the functionalconfiguration at the base station side according to the first embodimentof the present disclosure;

FIG. 21 is a flowchart showing signaling interaction process forimplementing a fourth schematic scheme according to the first embodimentof the present disclosure;

FIG. 22 is a flowchart showing signaling interaction process forimplementing dual stage DCI structure for MU-MIMO transmission of acontrol channel according to a second embodiment of the presentdisclosure;

FIG. 23 is a block diagram of an example showing functionalconfiguration of a device at a UE side according to the secondembodiment of the present disclosure;

FIG. 24 is a block diagram of an example showing functionalconfiguration of a device at a base station side according to the secondembodiment of the present disclosure;

FIG. 25 is a schematic diagram showing a schematic architecture ofGC-PDCCH, and a relationship between the GC-PDCCH and UE-specific PDCCHaccording to the second embodiment of the present disclosure;

FIG. 26 is a schematic diagram showing a first schematic schemeaccording to the second embodiment of the present disclosure;

FIG. 27 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the secondembodiment of the present disclosure;

FIG. 28 is a block diagram of another example showing the functionalconfiguration of the device at the base station side according to thesecond embodiment of the present disclosure;

FIG. 29 is a schematic diagram showing a second schematic schemeaccording to the second embodiment of the present disclosure;

FIG. 30 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the secondembodiment of the present disclosure;

FIG. 31 is a block diagram of another example showing the functionalconfiguration of the device at the base station side according to thesecond embodiment of the present disclosure;

FIG. 32A is a schematic diagram of a first example showing variation ofthe second schematic scheme according to the second embodiment of thepresent disclosure;

FIG. 32B is a schematic diagram of a second example showing variation ofthe second schematic scheme according to the second embodiment of thepresent disclosure;

FIG. 33 is a schematic diagram showing a relationship between GC-PDCCHand UE-specific PDCCH on time-frequency domain according to the secondembodiment of the present disclosure;

FIG. 34 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the secondembodiment of the present disclosure;

FIG. 35 is a block diagram of another example showing the functionalconfiguration of the device at the base station side according to thesecond embodiment of the present disclosure;

FIG. 36 is a flowchart of an example showing a method at a UE sideaccording to the first embodiment of the present disclosure;

FIG. 37 is a flowchart of an example showing a method at a base stationside according to the first embodiment of the present disclosure;

FIG. 38 is a flowchart of an example showing a method at a UE sideaccording to the second embodiment of the present disclosure;

FIG. 39 is a flowchart showing an example of a method at a base stationside according to the second embodiment of the present disclosure;

FIG. 40 is a block diagram showing a schematic structure of a personalcomputer as an available information processing device which can be usedaccording to an embodiment of the present disclosure;

FIG. 41 is a block diagram of a first example showing a schematicconfiguration of evolved node (eNB) to which the technology according tothe present disclosure may be applied;

FIG. 42 is a block diagram of a second example showing the schematicconfiguration of the eNB to which the technology according to thepresent disclosure may be applied;

FIG. 43 is a block diagram of an example showing a schematicconfiguration of a smart phone to which the technology according to thepresent disclosure may be applied; and

FIG. 44 is a block diagram of an example showing a schematicconfiguration of a vehicle navigation device to which the technologyaccording to the present disclosure may be applied.

DETAILED DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of the present disclosure are described below withreference to the drawings. For clarity and conciseness, not allcharacteristics of an actual embodiment are described in thespecification. However, it should be understood that manyembodiment-specific decisions, for example, conforming to restrictionsrelated to system and business, must be made when developing any actualembodiment, so as to achieve a specific goal of a developer. Theserestrictions may vary depending on embodiments. In addition, it shouldbe understood that, although development work may be complex andtime-consuming, the development work is merely a routine task for thoseskilled in the art who benefit from the present disclosure.

Here, it should be further noted that, in order to avoid obscuring thepresent disclosure due to unnecessary details, the drawings show onlydevice structures and/or processing steps that are closely related totechnical solutions of the present disclosure, and other details havelittle relevance to the present disclosure are omitted.

Before the embodiments of the present disclosure are described,“transparent” MU-MIMO transmission and “non-transparent” MU-MIMOtransmission are briefly introduced for facilitating understanding ofthe present disclosure.

In the “transparent” MU-MIMO transmission, as shown in FIG. 1, a basestation simultaneously schedules multiple UE to perform downlink MU-MIMOtransmission. A layer of signal flow for UE k and other three layers ofsignal flow (which may be for one or more other user equipment) sharethe same time-frequency resource by spatial multiplexing. However, theUE k does not know that there are other layers (which are shown bydotted line in FIG. 1). That is, the UE k does not know accurateinterference from other layers. In this case, in detecting a downlinkchannel, a receiver of the UE k attempts to recover only a downlinksignal sent to the UE k from the base station, and cannot performeffective processing for inter-layer interference.

In the “non-transparent” MU-MIMO transmission, as shown in FIG. 2, thebase station schedules signal flows of the UE k and one or more otheruser equipment on the same time-frequency resource, and notifies the UEk of other layers (which are shown by solid lines in FIG. 2), so thatthe receiver of the UE k recovers the downlink signal sent to the UE kfrom the base station by processing interferences from other layers.

Compared with the “transparent” MU-MIMO, the “non-transparent” MU-MIMOtransmission has the following advantages. The UE under the“non-transparent” transmission can know interferences between multipleusers, and thus suppress or remove interferences between multiple usersby using a more advanced receiver, thereby improving the throughout andreliability of the entire system. In addition, since cases of multipleuses are known, it is possible to measure interferences between multipleusers. The interference measurement here is performed based on DMRS.Possible disadvantages of the “non-transparent” transmission are asfollows. Extra signaling notification is required, so that the UE canknow other user equipment which shares the scheduled time-frequencyresource with the UE during multiple UE transmission. In addition, theadvanced receiver generally causes higher detection complexity,resulting in that the receiver consumes more computation and timeresource.

Therefore, in an embodiment according to at least one aspect of thepresent disclosure, “non-transparent” MU-MIMO transmission of a datachannel is implemented with less signaling overhead and less computationand time resource, so as to optimize the “non-transparent” MU-MIMOtransmission.

Hereinafter, description is performed in the following order. However,it should be noted that, for convenience of description, the embodimentsof the present disclosure are described in the following chapter order,but such chapter division and order does not limit the presentdisclosure. Practically, in implementing the technology according to thepresent disclosure, those skilled in the art may combine the embodimentsdescribed blow according to the principle of the present disclosure andactual situations, unless the embodiments conflict with each other.

1. “non-transparent” MU-MIMO transmission for a downlink data channel(First embodiment)

-   -   1-1. First schematic scheme    -   1-2. Second schematic scheme    -   1-3. Third schematic scheme    -   1-4. Fourth schematic scheme 2. MU-MIMO transmission for a        downlink control channel (Second embodiment)    -   2-1. First schematic scheme    -   2-2. Second schematic scheme    -   2-3. Variation of the second schematic scheme    -   2-4. Third schematic scheme

3. Method embodiments according to the present disclosure

-   -   3-1. First embodiment    -   3-2. Second embodiment

4. Computation device for implementing embodiments of the device andmethod according to the present disclosure

5. Application examples of the technology according to the presentdisclosure

-   -   5-1. Application example for a base station    -   5-2. Application example for user equipment

Subsequently, embodiments of the present disclosure are described indetail with reference to FIG. 1 to FIG. 44.

[1. “Non-Transparent” MU-MIMO Transmission for a Downlink Data Channel(First Embodiment)]

FIG. 3 is a block diagram of an example showing functional configurationof a device at a UE side according to a first embodiment of the presentdisclosure.

As shown in FIG. 3, a device 300 according to this example may include adetermination unit 302 and a decoding unit 304.

It should be noted that, functional units in the device shown in FIG. 3only represent logic modules divided according to the implementedspecific functions, and are not intended to limit the implementations.In an actual implementation, the functional units and modules may beimplemented as independent physical entities, or may be implemented by asingle entity (for example a processor (CPU or DSP), an integratedcircuit), which also adapts to description of other configurationexamples at the UE side later. Configuration examples of the functionalunits are described in detail in the following.

The determining unit 302 may be configured to determine, according tocontrol information, which is related to MU-MIMO transmission performedby target user equipment and other user equipment scheduledsimultaneously, from a base station, transmission related configurationof the other user equipment. The control information includesinformation indirectly indicating the transmission related configurationof the other user equipment.

Presently, in the LTE system, the base station notifies, via a downlinkcontrol channel, respective UE in MU-MIMO transmission of acorresponding DMRS port index, a scrambling ID, and the number of layersoccupied by a signal flow of the UE. Preferably, the transmissionrelated configuration here includes DMRS configuration. Preferably, theDMRS configuration may directly refer to a DMRS port index.Alternatively, the DMRS configuration may refer to information on apseudo random sequence and a corresponding orthogonal covered code (OCC)for generating DMRS. One pseudo random sequence may be used to generatemultiple orthogonal DMRSs with multiple OCC codes. Therefore, the samepseudo random sequence may be applied to multiple UE.

It should be noted that, the technology of the present disclosure isdescribed in the following detailed description by taking the DMRS portindex as an example of the transmission related configuration forconvenience. It should be understood that, the example does not limitthe present disclosure, and this description also adapts to other casesin which the DMRS configuration of the user equipment is represented byinformation in other form.

In order to cause the target UE to know DMRS configuration of other UEso as to implement the “non-transparent” MU-MIMO transmission, as adirect and simple manner, the DMRS configuration of other UE (forexample the DMRS port index) may be sent to the target UE one by one viaa downlink control channel. However, particularly in a great data amounttransmission service of the NR system, a total layer number of signalflow for the MU-MIMO transmission is generally great, that is, thenumber of the DMRS port indexes is great. In this case, the above mannerresults in great singling overhead and thus wasting valuable physicallayer signal resource. Therefore, the above manner is not suitable foran application scenario in which the NR has great data amounttransmission requirement.

In view of above, in solutions according to the present disclosure, thecontrol information for the MU-MIMO transmission of the target UEincludes information indirectly indicating DMRS configuration of otheruser equipment, so that the target UE can acquire the DMRS configurationof other user equipment based on the control information, with as fewsignaling overhead as possible.

The decoding unit 304 may be configured to decode, based on thedetermined transmission related configuration of other user equipment, asignal transmitted with MU-MIMO transmission and received from the basestation, to obtain a signal portion for the user equipment.

The decoding operation of the decoding unit 304 is further described indetail by taking serial interference removing as an example.

It is assumed that target UE is UE k, and the signal transmitted withMU-MIMO transmission and received from the base station is expressed asfollows:

$y_{k} = {{H_{k}P_{k}x_{k}} + {\sum\limits_{i \neq k}{H_{k}P_{i}x_{i}}} + {n_{k}.}}$

In which, H_(k) represents a channel from the base station to the UE k,P_(k) represents a precoding vector of the UE k, and n_(k) represents areceiver noise of the UE k. In addition, H_(k)P_(i)x_(i) representsinterference from UE i during the MU-MIMO transmission. In a case ofacquiring the DMRS configuration information of the UE i, the UE k mayfirst estimate an interference equivalent channel, that is, H_(k)P_(i),from the UE i, and attempt to decode data x_(i) of the UE i. If the UE kcan decode x_(i) and estimates H_(k)P_(i), an interference on the UE kfrom the UE i can be recovered, and the interference is subtracted fromthe above equation. By removing the interference from all UE (i≠k), thefollowing equation can be obtained:

y′ _(k) =H _(k) P _(k) x _(k) +n _(k).

Subsequently, the UE k may decode with the conventional linear receiverW to obtain the data sent to the UE k from the base station:

=Wy′ _(k) =W(H _(k) P _(k) x _(k) +n _(k))

It should be noted that, the decoding operation that the target dataflow is decoded based on the DMRS configuration information of otherinterference user equipment during the MU-MIMO transmission is onlyschematic. Those skilled in the art may decode the target data flowbased on the DMRS configuration information of the interference UE byusing other well-known decoding operation in the art or decodingoperations which may appear in the future. The decoding manner is notlimited in the present disclosure.

Here, it should be noted that the device 300 at the UE side may beimplemented as a chip or a device. For example, the device 300 mayfunction as the UE, and may include external devices such as a memory, atransceiver (optionally, shown by dotted line block in FIG. 3). Thememory may be configured to store programs to be executed to achievevarious function by the UE and related data information. The transceivermay include one or more communication interfaces to supportcommunication with different devices (for example the base station,other UE). The implementation of the transceiver is not limited here.This also adapts to the description of other configuration examples forthe UE side later.

Corresponding to the configuration example of the device at the UE sideshown in FIG. 3, examples of a base station side are further provided inthe present disclosure. FIG. 4 is a block diagram of an example showingfunctional configuration of a device at the base station side accordingto the first embodiment of the present disclosure.

As shown in FIG. 4, a device 400 according to this example may include acontrol information generation unit 402 and a transmission control unit404.

Similarly, it should be noted that, the functional units of the deviceshown in FIG. 4 represent only logic modules divided according to theachieved functions, and are not intended to limit the preset disclosure.In actual implementations, the functional units or modules may beimplemented as independent physical entities, or may be implemented as asingle entity (for example a processor (CPU or DSP), an integratedcircuit), which also adapts to the description of other configurationexamples of the base station side later. Configuration examples of thefunctional unit are described in detail hereinafter.

The control information generation unit 402 may be configured to: foreach of one or more user equipment in a group of user equipment, whichare simultaneously scheduled to perform MU-MIMO transmission, generatecontrol information related to the MU-MIMO transmission and control abase station to transmit the generated control information to this userequipment. The generated control information includes informationindirectly indicating transmission related configuration of other userequipment than this user equipment in the group of user equipment.Preferably, the transmission related configuration here includes DMRSconfiguration.

In some examples, for the group of user equipment which are scheduledsimultaneously to perform MU-MIMO transmission, receivers of differentuser equipment may have different processing capacities. For some userequipment of which the receiver has poor processing capacity, thereceivers of these user equipment cannot decode the target data flow bythe above linear interference removing manner, even if the DMRSconfiguration of other UE is informed. In this case, if the DMRSconfiguration of the interference UE is informed to these user equipmentvia the control channel, it results in waste of the physical layersignaling resource. Therefore, for these user equipment, preferably,“transparent” MU-MIMO transmission may be configured, that is, only DMRSconfiguration of these user equipment is informed.

In another aspect, for other user equipment of which the receiver hasstrong processing capacity, preferably, the “non-transparent” MU-MIMOtransmission according to the present disclosure may be configured. Thatis, information indirectly indicating the transmission relatedconfiguration of other UE in the group is included in the controlinformation to inform these user equipment, so that these user equipmentcan acquire and remove interference from other UE. The “one or more userequipment in the group of user equipment” described above indicate theuser equipment which can support and implement the “non-transparent”MU-MIMO transmission. In addition, in the description, the target userequipment refers to any user equipment in the one or more userequipment.

In this case, the MU-MIMO transmission for the data channel according tothe present disclosure includes both the “transparent” MU-MIMOtransmission and the “non-transparent” MU-MIMO transmission, which mayalso be referred to as hybrid transparent MU-MIMO transmission.

However, it should be noted that, in a case that the receivers of alluser equipment in the group performing the MU-MIMO transmission havestrong processing capacity and thus can support and implement the“non-transparent” MU-MIMO transmission, the control informationgeneration unit 402 at the base station side may generate the abovecontrol information for each of the group of user equipment. The basestation can flexibly determine UE to perform “transparent” MU-MIMOtransmission and UE to perform “non-transparent” MU-MIMO transmissionaccording to the present disclosure, based on the acquired relatedinformation of the user equipment. This is not limited in the presentdisclosure.

The transmission control unit 404 may be configured to control the basestation to simultaneously send signals to respective UE in the group ofUE on the same specific transmission resource.

In this way, the UE receiving the generated control information canacquire DMRS configuration of other UE in the group, and removes, asinterference, a signal of other UE which is superposed with a targetsignal of this UE for transmission, thereby demodulating the targetsignal from the received signal. In another aspect, for the UE which isconfigured to perform the “transparent” MU-MIMO transmission, the UEdirectly attempts to recover the target signal from the receivedsuperposed signals according to its DMRS configuration.

It should be noted that, the configuration example of the device at thebase station side described here corresponds to the configurationexample of the device at the UE side described above. Therefore, for thecontent not described in detail here, one may refer to the correspondingdescription above, and the details are not repeated here.

In addition, it should be noted that the device 400 at the base stationside may be implemented as a chip or a device. For example, the device400 may function as the base station, and may include external devicessuch as a memory, a transceiver (optionally, shown by a dotted line boxin FIG. 4). The memory may be configured to store programs to beexecuted to achieve various functions by the base station and relateddata information. The transceiver may include one or more communicationinterfaces to support communication with different devices (for example,UE, other base station). The implementations of the transceiver are notlimited here. This also adapts to the description of other configurationexample of the base station side later.

As examples rather than limiting, a first to a fourth schematic schemesfor indirectly indicating the DMRS configuration of an interference UEare described in detail respectively. However, it should be understoodthat, those skilled in the art can make appropriate amendments on theschematic schemes according to the principles of the present disclosure,to obtain other schemes for indirectly indicating the DMRS configurationof the interference UE. Such amendments apparently fall within theprotection scope of the present disclosure.

(1-1. First Schematic Scheme)

In the first schematic scheme, the control information from the basestation may include DMRS configuration of target user equipment and atotal layer number for MU-MIMO transmission. In the MU-MIMOtransmission, one layer of data flow corresponds to one DMRS port.Therefore, the total layer number for MU-MIMO transmission may beregarded as the total number of DMRS configurations or DMRS ports, orthe total number of data flow. Hereinafter, how to infer DMRSconfiguration of the interference UE from the DMRS configuration of thetarget UE and the total layer number for MU-MIMO transmission isdescribed in detail hereinafter.

FIG. 5 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure.

As shown in FIG. 5, a device 500 according to this example may include adetermination unit 502 and a decoding unit 504. A functionalconfiguration example of the decoding unit 504 is substantially the sameas the functional configuration example of the decoding unit 304described above with reference to FIG. 3, and details are not repeatedhere.

The determining unit 502 may include: a DMRS allocation schemeacquisition module 5021, a DMRS configuration set determination module5022 and a DMRS configuration determination module 5023.

The DMRS allocation scheme acquisition module 5021 may be configured toacquire a DMRS allocation scheme for MU-MIMO transmission by receivingfrom a base station or reading from a memory.

The DMRS allocation scheme here may indicate an allocation manner forDMRS ports, may be dynamically configured by the base station via highlayer signaling (for example RRC signaling), or may be a defaultallocation manner pre-stored in the memory. In a case that the DMRSallocation scheme is dynamically configured by the base station via thehigh layer signaling, the DMRS allocation scheme acquisition module 5021may decode the high layer signaling from the base station to obtain theDMRS allocation scheme.

The DMRS configuration set determination module 5022 may be configuredto determine a DMRS configuration set for the MU-MIMO transmissionaccording to at least the DMRS allocation scheme and the total layernumber. The DMRS configuration set here refers to a set consisting ofDMRS configurations of a group of UE participating in MU-MIMOtransmission.

The DMRS configuration determination module 5023 may be configured todetermine DMRS configuration other than DMRS configuration of this UE inthe DMRS configuration set, as DMRS configuration of other UE.

In a schematic implementation, the DMRS allocation scheme may include asequence of DMRS configurations. The sequence indicates multiple DMRSconfigurations which are arranged in an order and are used for MU-MIMOtransmission one time. In addition, the DMRS configuration setdetermination module 5022 may read DMRS configurations, the number ofwhich is equal to the total lay number, from the sequence of DMRSconfiguration in a predetermined order, as the DMRS configuration set.

In an example, in the LTE system, indexes of eight DMRS ports areantenna ports 7 to 14. It is assumed that the DMRS configurationsequence configured by the base station via RRC signaling is [7, 8, 11,13, 9, 10, 12, 14], the total layer number for MU-MIMO transmission is 6and the predetermined order or the usage order configured by the basestation is to read from the end of the sequence sequentially forexample. The DMRS configuration set determination module 5022 reads thelast six DMRS configurations 11, 13, 9, 10, 12, 14 from the sequence asthe DMRS configuration set for this MU-MIMO transmission. It is assumedthat the DMRS port index of the target UE is 10, and the DMRSconfiguration determination module 5023 of the target UE may determine11, 13, 9, 12, 14 as DMRS ports corresponding to interference data flowof other UE. In the NR system, indexes of the DMRS ports differ fromthat in the LTE system. Indexes of the DMRS ports in the NR system are1000-1011, which adapts to various examples described based on the LTEsystem in the present disclosure. Details are not repeated forbriefness.

In another schematic implementation, the DMRS allocation solution mayinclude a sequence of DMRS configurations. The sequence may not indicatea usage order of the included DMRS configurations. In addition to theDMRS configuration of the target UE and the total layer number, thecontrol information may further include a beginning layer number forMU-MIMO transmission in the configuration sequence. In this case, theDMRS configuration set determination module 5022 may be furtherconfigured to read, starting from a DMRS configuration corresponding tothe beginning layer number in the sequence of DMRS configurations, DMRSconfigurations, the number of which is equal to the total layer number,from the sequence of DMRS configurations sequentially, as the DMRSconfiguration set.

Specifically, the configured DMRS configuration sequence [7, 8, 11, 13,9, 10, 12, 14] is taken as an example again, and an index of each DMRSport in the sequence may be considered to correspond to a layer numberfor MU-MIMO transmission. For example, DMRS port 7 corresponds to layer1, DMRS port 11 corresponds to layer 3, and so on. It is assumed thatthe total layer number for MU-MIMO transmission is 6 and the beginninglayer number is 2, the DMRS configuration set determination module 5022reads sequentially, starting from a second DMRS port in the sequence,six DMRS configurations 8, 11, 13, 9, 10, 12 as the DMRS configurationset for the MU-MIMO transmission. It is assumed that the DMRS port ofthe target UE is 10, the DMRS configuration determination module 5023 ofthe target UE may determine 8, 11, 13, 9, 12 as DMRS ports correspondingto interference data flow of other UE.

According to the schematic implementation, the beginning layer numberfor MU-MIMO transmission is specified in the control information,thereby supporting more flexible use of the DMRS configuration forMU-MIMO transmission.

In another schematic implementation, the DMRS allocation scheme mayinclude information indicating a usage order of the DMRS configurations.For example, the DMRS allocation scheme indicates that the DMRSconfigurations are used in an ascending order (7 to 14) of the indexesof DMRS ports, in a descending order (14 to 7) of the indexes of DMRSports, or in a specified specific order. For example a sequence [7, 8,11, 13, 9, 10, 12, 14] indicating a usage order. In this case, the DMRSconfiguration set determination module 502 may be further configured toacquire DMRS configurations, the number of which is equal to the totallayer number, to form the DMRS configuration set, according to a usageorder indicated by the DMRS allocation scheme.

Specifically, it is assumed that the DMRS allocation solution indicatesthat the DMRS ports are used in an ascending order of indexes of theDMRS ports and the total layer number is 6, the DMRS configuration setdetermination module 5022 may directly acquire 7, 8, 9, 10, 11, 12 asthe DMRS configuration set for MU-MIMO transmission. It is assumed thata DMRS port index of the target UE is 10, and the DMRS configurationdetermination module 5023 of the target UE may determine 7, 8, 9, 11, 12as DMRS ports corresponding to interference data flow of other UE.

The schematic scheme in which the DMRS configuration of other UE in thegroup is inferred according to the DMRS configuration of the target UEand the total layer number for MU-MIMO transmission is described aboveas an example. However, it should be understood that, the above examplesare only for illustration rather than restrictive, those skilled in theart may make appropriate amendments on the schematic scheme according tothe principles of the present disclosure in conjunction with actualcases, and such amendments apparently fall within the protection scopeof the present disclosure.

Corresponding to the configuration example of the device at the UE side,a configuration example of the device at the base station side in thefirst schematic scheme is described in detail hereinafter. FIG. 6 is ablock diagram of another example showing the functional configuration ofthe device at the base station side according to the first embodiment ofthe present disclosure.

As shown in FIG. 6, a device 600 according to this example may include acontrol information generation unit 602 and a transmission control unit604. A functional configuration example of the transmission control unit604 is substantially the same as the functional configuration example ofthe transmission control unit 404 described above with reference to FIG.4. Details are not repeated here.

The control information generation unit 602 may be configured togenerate, for target user equipment in a group of user equipmentperforming MU-MIMO transmission, control information by including DMRSconfiguration of this user equipment and a total layer number of theMU-MIMO transmission, and control the base station to send the generatedcontrol information to the target UE, so that the target user equipmentinfers DMRS configuration of other interference UE according to thecontrol information and a DMRS allocation solution pre-stored orconfigured by the base station.

Preferably, in a case that the DMRS allocation solution is configured bythe base station, the device 600 may include a DMRS allocation solutiongeneration unit 606.

The DMRS allocation scheme generation unit 606 may be configured togenerate a DMRS allocation scheme for MU-MIMO, and control the basestation to send the generated DMRS allocation scheme to the target userequipment, so that the user equipment determines DMRS configuration ofother user equipment in the group of user equipment, based on at leastthe DMRS allocation scheme, the DMRS configuration of the user equipmentand the total layer number.

Preferably, the DMRS allocation scheme generation unit 606 includes thegenerated DMRS allocation scheme in high layer signaling (for exampleRRC signaling) to send to the target user equipment.

In a schematic implementation, the generated DMRS allocation scheme mayinclude a sequence of DMRS configurations, so that the user equipmentmay read DMRS configurations, the number of which is equal to the totallayer number, from the sequence in a predetermined order, as the DMRSconfiguration set for MU-MIMO transmission.

In another schematic implementation, the generated DMRS allocationscheme may include a sequence of DMRS configurations. The controlinformation generation unit 602 may be further configured to generatecontrol information by including a beginning layer number for MU-MIMOtransmission in the DMRS configuration sequence, in addition to the DMRSconfiguration of the target UE and the total layer number, so that theuser equipment can read, starting from DMRS configuration correspondingto the beginning layer number, DMRS configurations, the number of whichis equal to the total layer number, sequentially from the DMRSconfiguration sequence, as the DMRS configuration set for MU-MIMOtransmission.

In another schematic implementation, the generated DMRS allocationscheme may include information for a usage order of DMRS configurations,so that the user equipment can read DMRS configurations, the number ofwhich is equal to the total layer number, in the usage order, as theDMRS configuration set for MU-MIMO transmission.

It should be noted that, the DMRS allocation scheme generation unit 606shown in FIG. 6 (shown by dotted line block in FIG. 6) is optional. In acase that the DMRS allocation scheme is configured and stored in advancein the memory at the UE side, the DMRS allocation scheme generation unit606 may be omitted.

In addition, it should be noted that, the configuration example of thebase station side described here with reference to FIG. 6 corresponds tothe configuration example of the UE side described above with referenceto FIG. 5. Therefore, for the content not described here, one may referto the corresponding description above, and details are not repeatedhere.

In order to further facilitate understanding the first schematic scheme,signaling interaction process for implementing the first schematicscheme is described with reference to a flowchart shown in FIG. 7. FIG.7 is a flowchart showing signaling interaction process for implementingthe first schematic scheme according to the first embodiment of thepresent disclosure.

As shown in FIG. 7, first, in step S701, after RRC connection isestablished, the base station notifies UE k of DMRS allocation schemevia RRC signaling. Then, in step 702, the base station sends a downlinkreference signal (for example, channel state information-referencesignal CSI-RS) to the UE k to obtain a channel state. In step S703, theUE k feeds back measured channel state information to the base station.The base station performs MU-MIMO transmission scheduling based onchannel state information reported by multiple user equipment. In stepS704, the base station sends control information including DMRSconfiguration of the UE k and a total layer number for MU-MIMOtransmission to the UE k. The control information may be included inuser specific downlink control information (UE-specific DCI) transmittedon PDCCH. Then, in step S705, the base station transmits downlink datato a group of user equipment including the UE k on the sametime-frequency resource according to the determined MU-MIMO transmissionconfiguration. The UE k can obtain DMRS configurations of the UE k andother UE by decoding the received DCI, and thus demodulate the receiveddata information based on the DMRS configurations.

It should be noted that, the signaling interaction process describedabove with reference to FIG. 7 is only schematic rather thanrestrictive. Those skilled in the art may make amendments on the abovesignaling interaction process according to the principle of the presentdisclosure in conjunction with actual cases. For example, the order ofsteps in FIG. 7 is schematic rather than restrictive. For example, inorder to avoid obscuring the subject of the present disclosure, someinteraction process less related to the technology of the presentdisclosure is omitted in the above flowchart. In addition, some steps inthe above flowchart may be omitted. For example, in a case that the DMRSallocation solution is configured and stored in advance, theconfiguration of the DMRS allocation scheme in step S701 may be omitted(step S701 in FIG. 7 is shown by dotted line). All such amendments shallbe regarded to fall within the protection scope of the presentdisclosure, which are not listed one by one here.

It can be seen that according to the first schematic scheme describedabove, the DMRS configuration of other UE in the group is indirectlyindicated to the target UE by using the DMRS configuration of the targetUE and the total layer number for MU-MIMO transmission, so that the“non-transparent” MU-MIMO transmission can be achieved with lesssignaling overhead, thereby being beneficial to optimize the systemperformance of MU-MIMO transmission.

(1.2 Second Schematic Scheme)

In a second schematic scheme according to the present disclosure,information on transmission related configuration of interference UE inthe group is indirectly informed to the target UE by using interferencemeasurement resource. Preferably, the interference measurement resourcemay include Non-Zero Power CSI-RS (NZP CSI-RS) resource. In addition,the interference measurement resource may further include channel stateinformation interference measurement (CSI-IM) resource. The technologyof the present disclosure is described below by taking the NZP CSI-RSresource as an example of the interference measurement resource. Itshould be understood that, this is only schematic rather thanrestrictive, and the technology described below may be similarly appliedto other interference measurement resource.

Presently, in the NR system, multiple user interference measurementbased on NZP CSI-RS is supported. Therefore, in the present disclosure,interference information in MU-MIMO transmission is indirectly indicatedbased on CSI-RS resource selected in the multiple user interferencemeasurement, so that the user equipment can indirectly infer DMRSconfiguration corresponding to data flow of the interference UEaccording to information of the CSI-RS resource.

Specifically, a mapping relationship between DMRS ports and CSI-RSresource or antenna ports for transmitting CSI-RS resource (alsoreferred to as CSI-RS port) is established in advance. FIG. 8 is aschematic diagram of an example showing a mapping relationship betweenDMRS ports and CSI-RS resource or CSI-RS ports according to the firstembodiment of the present disclosure.

In a schematic implementation, a mapping relationship between CSI-RSresource and DMRS ports may be established. For example, as shown inFIG. 8, taking the NR system as an example, CSI-RS resource 1 is mappedto DMRS port 1007, 1008 and 1011; CSI-RS resource 2 is mapped to DMRSport 1007, 1003; and CSI-RS resource 3 is mapped to DMRS ports 1011,1004.

Alternatively, in another schematic implementation, a mappingrelationship between CSI-RS ports and DMRS ports may be established.CSI-RS supports setting of a part or all of 1, 2, 4, 8, 12, 16, 24 and32 antenna ports. For example, CSI-RS supports 32 antenna ports, thatis, CSI-RS may be transmitted via 32 antenna ports. In the LTE, CSI-RSis transmitted via one or more in antenna ports 15-46 (port indexes are15-46). In addition, the supported antenna port may be determinedaccording to the capability of the terminal device, setting of RRCparameters and/or set transmission modes. In the NR, there are 32 CSI-RSports (actual antenna port indexes are 3000 to 3031 in the NR system)and 12 DMRS ports (actual antenna ports indexes are 1000 to 1011 in theNR system) in total, and thereby mapping of CSI-RS ports to DMRS portscan be implemented. For example, one CSI-RS port may be uniquely mappedto one DMRS port, while one DMRS port may be mapped to multiple CSI-RSports, and thereby a unique DMRS port can be determined according to thecorresponding CSI-RS port. For example, as shown in FIG. 8, CSI-RS ports3015 and 3018 each are mapped to DMRS port 1007, CSI-RS port 3016 ismapped to DMRS port 1008, CSI-RS ports 3017 and 3030 are mapped to DMRSport 1011, and so on. Examples are not listed one by one here.

In addition, it should be noted that, a certain correspondence existsbetween CSI-RS resources and CSI-RS ports. The correspondence may beconfigured in advance by the base station via RRC. In this way, the userequipment can determine a corresponding DMRS port according toindication information on the CSI-RS resource or CSI-RS port from thebase station and the mapping relationship, regardless of the mappingrelationship being established as a mapping relationship between theCSI-RS resource and the DMRS port or between the CSI-RS port and theDMRS port.

Subsequently, in a multiple user interference measurement phase, thebase station may configure multiple interference measurement resourcescorresponding to multiple user combinations, for example CSI-RSresources, for multiple UE on an RRC layer. A mapping relationship knownby both the base station and the UE exists between the DMRS ports andthe CSI-RS resource or CSI-RS port.

Each CSI-RS resource may correspond to a MU combination. As shown inFIG. 8, NZP CSI-RS resource 1 corresponds to a MU combination of UE 1,UE m and UE n, NZP CSI-RS resource 2 corresponds to a MU combination ofUE 2 and UE 4, and NZP CSI-RS resource 3 corresponds to a MU combinationof UE j and UE t. The user equipment measures multiple CSI-RS resourcesand reports measurement results to the base station. The base stationruns a multiple user scheduling algorithm after receiving themeasurement results reported by multiple user equipment, to determine agroup of user equipment to perform MU-MIMO transmission. Then, the basestation may select CSI-RS resource corresponding to a MU schedulingresult from the configured multiple CSI-RS resource, and inform the userequipment of the selected CSI-RS resource. The user equipment can obtaina DMRS port of other UE participating in MU-MIMO transmission accordingto the known mapping relationship, thereby implementing the“non-transparent” MU-MIMO transmission.

It should be noted that, in the second schematic scheme described above,interference during MU-MIMO transmission of the data channel issimulated based on the antenna port of NZP CSI-RS, and beamformingconsistent with DMRS is used for NZP CSI-RS. The NZP CSI-RS shouldoccupy the same or similar frequency band resource as DMRS, for example,occupying the same sub-band resource.

Configuration examples of the UE side and the base station forimplementing the second schematic scheme are described in detailhereinafter.

FIG. 9 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure.

As shown in FIG. 9, a device 900 according to this example may include adetermination unit 902 and a decoding unit 904. The functionalconfiguration example of the decoding unit 904 is substantially the sameas a functional configuration example of the decoding unit 304 describedabove with reference to FIG. 3, and details are not repeated here.

The determination unit 902 may be configured to determine transmissionrelated configuration of interference UE based on control informationfrom the base station. The control information may include informationindicating interference measurement resource selected form one or moreinterference measurement resource by the base station or informationindicating an antenna port for sending the selected interferencemeasurement resource.

Preferably, the interference measurement resource may include NZP CSI-RSresource. In addition, preferably, the information indicating theselected interference measurement resource may include CSI-RS resourceindicator (CRI), and thus the base station may include CRI of theselected CSI-RS resource in UE-specific downlink control information(UE-specific DCI) for example, to notify the target UE.

A specific functional configuration example of the determination unit902 is described in detail with reference to FIG. 10. FIG. 10 is a blockdiagram of an example showing the functional configuration of thedetermination unit in the device at the UE side according to the firstembodiment of the present disclosure.

As shown in FIG. 10, the determination unit 902 may further include amapping relationship acquisition module 1001 and a DMRS configurationdetermination module 1002.

The mapping relationship acquisition module 1001 may be configured toacquire information indicating a mapping relationship between the DMRSconfiguration and interference measurement resource or an antenna portfor sending the interference measurement resource, by receiving from thebase station or reading from the memory.

Specifically, the mapping relationship between the DMRS port and theCSI-RS resource or CSI-RS port described above with reference to FIG. 8may be stored in the memory at the UE side in advance, or may bedynamically configured by the base station via high layer signaling (forexample RRC signaling). In a case that the mapping relationship isdynamically configured by the base station, the mapping relationshipacquisition module 1001 may decode the high layer signaling (for examplethe RRC signaling) from the base station, to acquire the mappingrelationship.

The DMRS configuration determination module 1002 may be configured todetermine, based on the acquired mapping relationship, the DMRSconfiguration corresponding to the interference measurement resourceselected by the base station, as DMRS configuration of other userequipment.

Specifically, as an example, returning to refer to FIG. 8, if the CRIincluded in the control information from the base station indicates thatthe selected interference measurement resource is CSI-RS resource 1 andthe acquired mapping relationship is a mapping relationship between theCSI-RS resource and the DMRS port, the DMRS configuration determinationmodule 1022 may directly determine that DMRS ports corresponding toCSI-RS resource 1 are 7, 8, 11, and determine these three ports as DMRSconfigurations of interference UE in the group. Alternatively, if theacquired mapping relationship is a mapping relationship between theCSI-RS port and DMRS port, the DMRS configuration determination module1002 is required to determine a CSI-RS port corresponding to CSI-RSresource indicated by CRI, according to a correspondence between CSI-RSresources and CSI-RS ports configured via RRC by the base station orpre-stored. Then, the DMRS configuration determination module 1002determines the DMRS port corresponding to the CSI-RS port as the DMRSconfiguration of the interference UE, according to the mappingrelationship between the CSI-RS port and the DMRS port.

In another aspect, in a case that the control information from the basestation includes information indicating the CSI-RS port, the DMRSconfiguration of the interference UE can be determined similarly.Details are not repeated herein.

It should be noted that, the DMRS configuration of the interference UEis indirectly indicated by using CRI with a priority, so as to reducesignaling overhead of the physical layer.

Returning to refer to FIG. 9, preferably, the device 900 may include aninterference measurement unit 906. The interference measurement unit 906may be configured to perform multiple user interference measurementbased on the interference measurement resource configured by the basestation and report measurement results to the base station, so that thebase station selects from the configured multiple interferencemeasurement resources based on the measurement results. A functionalconfiguration example of the interference measurement unit 906 isdescribed in detail with reference to FIG. 11. FIG. 11 is a blockdiagram of an example showing specific functional configuration of aninterference measurement unit in a device at the UE side according tothe first embodiment of the present disclosure.

As shown in FIG. 11, the interference measurement unit 906 according tothis example may include an interference measurement resourceacquisition module 1101, a measurement module 1102 and a control module1103.

The interference measurement resource acquisition module 1101 may beconfigured to decode high layer signaling received from the basestation, to acquire one or more interference measurement resources.

Specifically, in an example, if the base station configures M NZP CSI-RSresource, that is, CSI-RS resource 1 to CSI-RS resource M, for the userequipment via high layer signaling, the interference measurementresource acquisition module 1101 may acquire M NZP CSI-RS resources bydecoding the RRC signaling.

The measurement module 1102 may be configured to perform interferencemeasurement based on one or more interference measurement resources, andgenerates measurement result indication corresponding to each of the oneor more interference measurement resources.

Specifically, in an example, the measurement module 1102 may measure theM CSI-RS resources respectively, and generates measurement resultindications corresponding to the M CSI-RS resources. Preferably, themeasurement result indication may include at least one of multiple userchannel quality indication (MU-CQI), reference signal receiving power(RSRP) and reference signal receiving quality (RSRP). Taking the MU-CQIas an example here, the measurement module 1102 generates MU-CQI 1 toMU-CQI M corresponding to the M CSI-RS resources respectively.

The control module 1103 may be configured to control the user equipmentto feed back all or a part of the multiple measurement indications tothe base station, so that the base station selects the selectedinterference measurement resource from one or more interferencemeasurement resources.

Specifically, in an example, the control module 1103 may control theuser equipment to report all M MU-CQIs to the base station, so that thebase station selects appropriate CSI-RS resources from the M CSI-RSresources based on measurement results from other user equipment and aspecific network status. In another aspect, in order to reducetransmission overhead and signaling overhead, the control module 1103may control the user equipment to report only a part of MU-CQI to thebase station. For example, only MU-CQI greater than a predeterminedthreshold is reported. The base station selects from only CSI-RSresources for which the measurement results are received.

Corresponding to the configuration example of the UE side, aconfiguration example of the base station side is described hereinafter.FIG. 12 is a block diagram of another example showing a device at thebase station side according to the first embodiment of the presentdisclosure.

As shown in FIG. 12, a device 1200 according to this example may includea control information generation unit 1202 and a transmission controlunit 1204. A functional configuration example of the transmissioncontrol unit 1204 is substantially the same as the functionalconfiguration example of the transmission control unit 404 describedabove with reference to FIG. 4. Details are not repeated here.

The control information generation unit 1202 may be configured togenerate control information for MU-MIMO transmission based on multipleuser interference measurement, to indirectly indicate transmissionrelated configuration of interference UE to the target UE.

A specific functional configuration example of the control informationgeneration unit 1202 is described in detail with reference to FIG. 13below. FIG. 13 is a block diagram of an example showing specificfunctional configuration of the control information generation unit ofthe device at the base station side according to the first embodiment ofthe present disclosure.

As shown in FIG. 13, the control information generation unit 1202according to this example may include a resource configuration module1301, a resource selection module 1302 and a control informationgeneration module 1303.

The resource configuration module 1301 may be configured to configureone or more interference measurement resources for each of a group ofuser equipment which is to perform MU-MIMO transmission.

Specifically, the resource configuration module 1302 may configuremultiple NZP CSI-RS resources for each user equipment, for example viahigh layer RRC signaling. The multiple CSI-RS resources may correspondto multiple MU combinations.

The resource selection module 1302 may be configured to, for target userequipment according to measurement result indications fed back by thetarget user equipment and other user equipment based on the configuredone or more interference measurement resources, select interferencemeasurement resources from one or more interference measurementresources, that is, select a multiple user combination for MU-MIMOtransmission, and generate indication information of the selectedinterference measurement resource or indication information of anantenna port for sending the selected interference measurement resource.

Specifically, the base station sends a downlink reference signal CSI-RSto each user equipment based on the configured multiple CSI-RSresources, and receives measurement result indications for one or moreof multiple CSI-RS resources reported by the user equipment. Themeasurement result indication may include at least one of MU-CQI, RSRPand RSRQ. Then, the resource selection module 1302 of the base stationsside can determine, based on for example MU-CQI reported by multipleuser equipment, a group of user equipment to perform MU-MIMOtransmission by using the known MU scheduling algorithm, therebydetermining the CSI-RS resource for the target user equipment. For thespecific MU scheduling algorithm, one may refer to the description inthe conventional technology, and details are not repeated here.

The control information generation module 1303 may be configured togenerate control information by including the indication information,for target user equipment in the determined group of user equipment.

Specifically, the control information generation module 1303 may includeindication information of the selected CSI-RS resource (for example CRI)or indication information of the corresponding CSI-RS port (for exampleCSI-RS port index) in the control information, to send to the targetuser equipment via UE-specific DCI on PDCCH, for example. Thus, thetarget user equipment may acquire the included CRI or CSI-RS port indexby decoding the received DCI, and determine DMRS configuration of theinterference UE further based on known mapping relationship.

Returning to refer to FIG. 12, preferably, the device 1200 may include amapping relationship configuration unit 1206.

The mapping relationship configuration unit 1206 may be configured to,for the target user equipment, generate information indicating a mappingrelationship between the interference measurement resource or an antennaport for sending the interference measurement resource and the DMRSconfiguration, and controls a base station to send the informationindicating the mapping relationship to the target user equipment, sothat the target user equipment determines DMRS configuration ofinterference UE in the group based on the CSI-RS resource or portindicated by the control information, and the mapping relationship.

Preferably, the mapping relationship configuration unit 1206 mayconfigure for example the mapping relationship described with referenceto FIG. 8 via high layer signaling, for example, includes the mappingrelationship in the RRC signaling to send to the target user equipment.

It should be noted that, the mapping relationship configuration unit1206 is optional (shown by a dotted line box in FIG. 12). In a case thatthe mapping relationship is pre-configured and stored in the memory atthe UE side, the user equipment may directly read the mappingrelationship from the memory. Thus the mapping relationshipconfiguration unit 1206 may be omitted.

In addition, it should be noted that, the configuration examples of thebase station side described with reference to FIG. 12 and FIG. 13correspond to the configuration example of the UE side described above.Therefore, for content not described in detail here, one may refer tothe description at the above corresponding position, and details are notrepeated here.

In order to further understand the above second schematic scheme,signaling interaction process for implementing the second schematicscheme is described below with reference to a flowchart shown in FIG.14. FIG. 14 is a flowchart showing signaling interaction process forimplementing the second schematic scheme according to the firstembodiment of the present disclosure.

As shown in FIG. 14, first, after RRC connection is established, in stepS1401, the base station configures, via RRC signaling, for example M NZPCSI RS resources and a mapping relationship between DMRS port and CSI-RSresource or CSI-RS port, for user equipment k. Then, in step S1402, thebase station sends a downlink reference signal CSI-RS to the userequipment k based on the M NZP CSI-RS resources. The user equipment kmeasures M NZP CSI RS resources, and reports, for example, MU-CQIs asthe measurement result to the base station in step S1403. The userequipment k may report all M MU-CQIs to the base station, or report, forexample, only MU-CQIs greater than a predetermined threshold to the basestation. The base station performs MU-MIMO transmission scheduling basedon MU-CQIs reported by multiple user equipment, to select one NZP CSI-RSresource from M NZP CSI-RS resources. In step S1404, the DMRSconfiguration of the user equipment k and the control informationincluding for example CRI of the selected CSI-RS resource is sent to theuser equipment k via for example DCI. Then, in step S1405, the basestation transmits downlink data to a group of user equipment includingthe user equipment k on the same time-frequency resource. The userequipment k may obtain its DMRS configuration and DMRS configuration ofother UE in the group by decoding the received DCI, and thus demodulatethe received data information based on the DMRS configurations.

It should be noted that, the signaling interaction process describedabove with reference to FIG. 14 is only schematic rather thanrestrictive, those skilled in the art may make amendments on the aboveinteraction process according to the principle of the present disclosurein conjunction with actual situations. For example, the order of stepsin FIG. 14 is schematic rather than restrictive. For example, in orderto avoid obscuring the subject of the present disclosure, someinteraction process less related to the technology of the presentdisclosure is omitted in the above flowchart. In a case that the mappingrelationship is preconfigured and stored, the base station may notinform the user equipment of the mapping relationship in step S1401. Allsuch amendments shall be regarded to fall within the scope of thepresent disclosure, and details are not repeated here.

According to the second schematic scheme of the present disclosure,according to the existing multiple user interference measurement basedon the interference measurement resources and the pre-establishedmapping relationship between the DMRS configuration and the interferencemeasurement resource or corresponding antenna ports, the DMRSconfiguration corresponding to the interference data flow during theMU-MIMO transmission is indirectly indicated to the target userequipment by using the interference measurement resource, so that theuser equipment can obtain the related interference information withoutsignificantly increasing a processing load and signaling overhead,thereby implementing the “non-transparent” MU-MIMO transmission andbeing beneficial to optimize the system performance.

(1-3. Third Schematic Scheme)

In a third schematic scheme of the present disclosure, the DMRSconfiguration for MU-MIMO transmission is indirectly informed based on atransmission configuration indicator (TCI) mechanism. The existing TCImechanism is introduced simply hereinafter.

In the present 3GPP 5G standardized development, a mechanism that Quasico-location (QCL) relationship is informed with TCI is determined.Specifically, two antenna ports can be represented as QCL in a case ofmeeting a predetermined condition. The predetermined condition is that awide domain performance of a transmission channel for bearing symbols ina certain antenna port can be inferred from a transmission channel forbearing symbols in other antenna port. The wide domain performanceincludes delay extension, Doppler extension, Doppler frequency shift,average gain, average delay and/or spatial reception. For example, ifthe TCI indicates CSI-RS port 15 and DMRS port 7 have QCL relationshipin the space dimension, that is, two reference signals have consistentspatial features from a transmission end to a reception end. TCI is amechanism supporting the base station to inform the user equipment ofthe QCL relationship. The existing TCI mechanism is briefly introducedhereinafter.

For example, it is assumed that for a certain antenna port or CSI-RSresource (for example CSI-RS port 3015 or CSI-RS resource ID5), the basestation configures M TCI states for each UE via UE-specific RRC. The MTCI states include {downlink reference signal 1|QCL_type1, downlinkreference signal 2|QCL_type2, . . . , downlink reference signalM|QCL_typeM}, which indicates that downlink reference signal 1 andCSI-RS port 3015 have co-location of QCL_type1, downlink referencesignal 2 and CSI-RS port 3015 have co-location of QCL_type 2, and so on.

The downlink reference signal may include CSI-RS, CRS, DMRS and so on.QCL_type indicates a type of co-location. Presently, there are fourtypes of co-location in total: QCL type A: Doppler frequency shift,Doppler extension, average delay, delay extension (frequency domain andtime domain); QCL type B: Doppler frequency shift, Doppler extension(frequency domain); QCL type C: average delay, Doppler frequency shift(simplified frequency domain and time domain); and QCL type D: spatialreception (spatial domain).

According to the third schematic scheme of the present disclosure, theDMRS configuration of the MU-MIMO transmission group is indirectlyindicated to the user equipment based on the TCI mechanism.Configuration examples of the UE side and the base station side forimplementing the third schematic scheme are respectively described indetail hereinafter.

FIG. 15 is a block diagram of another example showing the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure.

As shown in FIG. 15, a device 1500 according to this example may includea determination unit 1502 and a decoding unit 1504. A functionconfiguration example of the decoding unit 1504 is substantially thesame as the functional configuration example of the decoding unit 304described with reference to FIG. 3. Details are not described here.

The determination unit 1502 may include a TCI configuration acquisitionmodule 1521 and a DMRS configuration determination module 1522.

The TCI configuration acquisition module 1521 may be configured toacquire TCI configuration including a first number of TCI states fromthe base station. Each TCI state in the TCI configuration includes oneDMRS configuration and a co-location type indication. The co-locationtype indication indicates the DMRS configuration is an interference DMRSconfiguration during MU-MIMO transmission.

Specifically, for target user equipment, the base station may configureTCI configuration including a first number of TCI states (indicated as MTCI states here) for example via UE-specific RRC, to indicate M DMRSports which can be used for MU-MIMO transmission. In the schemeaccording to the present disclosure, the TCI state in the TCIconfiguration indicates interference DMRS configuration in MU-MIMOtransmission, rather than QCL relationship between two antenna ports.Therefore, in a schematic implementation, one co-location type may beadded in addition to the existing four co-location types A to D. Theadded co-location type may be indicated as QCL type E for example, fordistinguishing from the existing TCI usage. As an example, theconfigured M TCI states may include {DMRS 1|QCL_typeE, DMRS 2|QCL_typeE,. . . DMRS M|QCL_typeE}, to indicate that DMRS 1 to DMRS M areinterference ports during MU-MIMO transmission in this case.Alternatively, in another example, for the TCI configuration for MU-MIMOtransmission, the co-location type included in each TCI state may bedefault, and information of one bit for example is added in the RRCsignaling to indicate whether the configured TCI is used to indicate QCLor used for MU-MIMO transmission.

In this way, the TCI configuration acquisition module 1521 at the UEside may acquire M TCI states configured for MU-MIMO transmission bydecoding high layer RRC signaling from the base station, and know thatDMRS ports indicated by the M TCI states may function as interferenceports in the MU-MIMO transmission.

The DMRS configuration determination module 1522 may be configured todetermine, according to information indicating usage configuration ofthe TCI state included in control information from the base station,DMRS configuration corresponding to a used TCI state in the first numberof configured TCI states as DMRS configuration of other user equipment.

Specifically, for the target user equipment, the base station maygenerate, according to DMRS configuration of other UE which issimultaneously scheduled with the target user equipment to performMU-MIMO transmission, usage configuration information indicating TCIstates in the configured M TCI states, whose corresponding DMRSconfiguration functions as DMRS configuration of other UE.

Preferably, in a schematic implementation, the usage configurationinformation may indicate information on the number of the TCI stateswhose DMRS configuration functions as interference DMRS configuration inMU-MIMO transmission, among the M TCI states. The usage configurationinformation is included in UE-specific DCI to send to the userequipment, and thus the DMRS configuration determination module 1522 atthe UE side can read the TCI states of the predetermined numberindicated by the usage configuration information from the configured MTCI states in a predetermined order (for example, in a descending order,in an ascending order or reading sequentially from head to end), anddetermine DMRS configuration corresponding to the read TCI state as theinterference DMRS configuration.

Preferably, in another schematic implementation, the usage configurationinformation may be bitmap information. For example, the used DMRS portis indicated as 1 in a bitmap, and the unused DMRS port is indicated as0 in the bitmap. The usage configuration information may be included inUE-specific DCI and transmitted to the user equipment, and thus the DMRSconfiguration determination module 1522 at the UE side can acquire thebitmap information by decoding the DCI from the base station, anddetermine a DMRS port corresponding to the TCI state indicated as “1” inthe bitmap information as the interference DMRS port. Therefore, theuser equipment can perform corresponding interference removing and datademodulation, thereby implementing the “non-transparent” MU-MIMOtransmission using the TCI mechanism.

In addition, it should be noted that, bits of the information indicatingthe usage configuration of the TCI state in the DCI may be fixed, so asto facilitate demodulating physical layer signaling by the userequipment. For example, in a case that the usage configurationinformation is used to indicate the number of the used TCI states, theusage configuration information may be fixed as 3 bits for example, andthus can indicate at most 8 interference DMRS configurations. In anotheraspect, in a case that the usage configuration information is bitmapinformation, the usage configuration information may be fixed as 8 bitsfor example. In a case that M is less than 8, deficient digits in thebitmap information indicating usage configuration of M TCI states may besupplemented with 0.

In another aspect, in a case that M is greater than 8, in order to savephysical layer signaling overhead and solve the problem that reservedbits in DCI are insufficient, preferably, the base station may activatea second number (for example N=8) of TCI states from the M TCI statesvia UE-specific MAC control element (MAC CE). The activation operationmay be implemented by bitmap information. For example, an activated TCIstate is indicated as 1, and a non-activated TCI state is indicated as0. Then, the base station informs the target user equipment of usageconfiguration of the activated N TCI states in MU-MIMO transmission byusing DCI of the physical layer.

Therefore, preferably, the determination unit 1502 at the UE side mayfurther include an activation configuration determination module 1523.

The activation configuration determination module 1523 may be configuredto determine, according to information indicating activationconfiguration of the TCI state from the base station, a second number ofactivated TCI states among the first number of TCI states. Preferably,the second number is 8.

Specifically, the activation configuration determination module 1523 mayobtain activation configuration information of the TCI states in a formof bitmap by decoding the MAC CE from the base station, and determinethe TCI state corresponding to the bit “1″” as the activated TCI state.In this way, the activation configuration determination module 1523 candetermine the activated TCI states, for example 8, among the M TCIstates.

In this case, the usage configuration information indicating the TCIstate from the base station may be information indicating usageconfiguration of the activated 8 TCI states. For example, the usageconfiguration information may be information indicating the number ofTCI states for MU-MIMO transmission among 8 TCI states (3 bits), or maybe bitmap information indicating whether each of the 8 TCI states isused for MU-MIMO transmission (8 bits), and thus the DMRS configurationdetermination module 1522 can read, according to usage configurationinformation, the indicated number of TCI states in a predetermined orderfrom the activated 8 TCI states, and determines the corresponding DMRSconfiguration as the interference DMRS configuration. Alternatively, theDMRS configuration determination module 1522 may determine, according tothe bitmap information of 8 bits, DMRS configuration corresponding tothe TCI state indicated as “1” among the activated 8 TCI states, as DMRSconfiguration of other user equipment.

It should be noted that, the activation configuration determinationmodule 1523 is optional (shown by a dotted line box in FIG. 15). In acase that M is less than or equal to 8, it is unnecessary for the basestation to perform activation by using MAC CE, and thus it isunnecessary to provide the activation configuration determination module1523 at the UE side.

Corresponding to the configuration example at the UE side, aconfiguration example at the base station side is described hereinafter.FIG. 16 is a block diagram showing another example of the functionalconfiguration of the device at the base station side according to thefirst embodiment of the present disclosure.

As shown in FIG. 16, a device 1620 according to this example may includea control information generation unit 1630 and a transmission controlunit 1640. A functional configuration example of the transmissioncontrol unit 1640 is substantially the same as the functionalconfiguration example described above with reference to FIG. 4. Detailsare not repeated here.

The control information generation unit 1630 may further include a TCIconfiguration generation module 1631, a usage configuration informationgeneration module 1632 and a control information generation module 1633.

The TCI configuration generation module 1631 may be configured togenerate TCI configuration including a first number of TCI states, andcontrol a base station to send the TCI configuration to target userequipment. In the TCI configuration, each TCI state includes one DMRSconfiguration and a co-location type indication. The co-location typeindication indicates that the DMRS configuration is interference DMRSconfiguration in MU-MIMO transmission.

Specifically, the TCI configuration generation module 1631 may generateTCI configuration including for example M TCI states, and include theTCI configuration in for example UE-specific RRC signaling to send tothe target user equipment. In an example, the configured M TCI statesmay include {DMRS 1|QCL_typeE, DMRS 2|CQL_typeE, . . . DMRS M|QCL_typeE}. In which, QCL_typeE indicates that the DMRS port is an interferenceport in MU-MIMO transmission, to distinguish from the TCI stateindicating the co-location type in the conventional technology.

The usage configuration information generation module 1632 may beconfigured to generate information indicating usage configuration of afirst number of TCI states, according to DMRS configuration ofinterference UE other than the target UE in a group of user equipmentperforming MU-MIMO transmission.

Preferably, for example, the usage configuration information may beinformation indicating the number of TCI states whose DMRS configurationfunctions as interference DMRS configuration in MU-MIMO transmission,among the first number of TCI states. Alternatively, preferably, forexample, the information indicating usage configuration of the TCIstates may be bitmap information. For example, the usage configurationinformation generation module 1632 may mark a TCI state corresponding toDMRS configuration of interference UE as 1, and mark other non-used TCIstate as 0, to generate the bitmap information.

The control information generation module 1633 may be configured togenerate control information by including the generated informationindicating usage configuration of the TCI states. Preferably, the usageconfiguration information may be included in UE-specific DCI to send tothe target UE, to indirectly indicate DMRS configuration of interferenceUE in the MU-MIMO transmission group to the target UE. Thus, the targetUE performs interference removing and data demodulation to recover atarget data flow, thereby implementing the “non-transparent” MU-MIMOtransmission.

Preferably, the control information generation unit 1630 may include anactivation configuration information generation module 1634. Theactivation configuration information generation module 1634 may beconfigured to active a second number of TCI states from the first numberof TCI states, and generate activation configuration informationindicating the activated second number of TCI states.

Specifically, in a case that the number M of TCI states configured byRRC is too large, for example M is greater than 8, the base station mayactivate N (for example N is 8) TCI states from M TCI states andindicate the activation operation by activation configurationinformation in a form of bitmap, in order to save physical layersignaling overhead and maintain consistency of formats of the physicallayer signaling. For example, the activated TCI state is indicated as 1in the bitmap information, and the non-activated TCI state is indicatedas 0 in the bitmap information. The activation configuration informationin a form of bitmap may be included in UE-specific Mac CE to send to thetarget UE.

Then, the usage configuration information generation module 1632 maygenerate, according to DMRS configuration of interference UE in MU-MIMOtransmission, usage configuration information indicating usage of theactivated TCI states, for example, information on the number of TCIstates for MU-MIMO transmission among the activated N TCI states. Forexample, among the activated N TCI states, the TCI state correspondingto interference DMRS configuration is marked as 1, and the non-used TCIstate is marked as 0, thereby generating bitmap information of N bits.

In this way, the target UE may determine DMRS configuration of theinterference UE according to activation configuration informationreceived from the MAC layer and the usage configuration informationreceived from the physical layer, thereby performing interferenceremoving and data demodulating.

It should be noted that, the activation configuration informationgeneration module 1634 is optional (shown by a dotted line block in FIG.16). In a case that the number of TCI states configured by RRC is lessthan or equal to 8 for example, the activation operation may be omitted.Thus, it is unnecessary to provide the activation configurationinformation generation module 1634.

In addition, it should be noted that, the configuration example at thebase station side described here with reference to FIG. 16 correspondsto the configuration example at the UE side. Therefore, for content notdescribed in detail here, one may refer to the description at thecorresponding position above, and details are not repeated here.

In order to further understand the third schematic scheme, signalinginteraction process for implementing the third schematic scheme isdescribed below with reference to a flowchart shown in FIG. 17. FIG. 17is a flowchart showing signaling interaction process for implementingthe third schematic scheme according to the first embodiment of thepresent disclosure.

As shown in FIG. 17, first, after RRC connection is established, thebase station configures TCI configuration for MU-MIMO transmissionincluding for example M TCI states for user equipment k via RRCsignaling, in step S1701. Then, in step S1702, the base stationactivates N TCI states from M TCI states, and includes informationindicating activation configuration of the TCI states in MAC CE to sendto the user equipment k. Subsequently, in step S1703, the base stationsends downlink reference signal CSI-RS to the user equipment k to obtainchannel state information, and the use equipment k sends measuredchannel state information to the base station in step 1704. Then, instep S1705, the base station performs MU-MIMO transmission schedulingbased on channel state information reported by the user equipment devicek and other user equipment in conjunction with specific network status,thus generates information indicating usage configuration of theactivated N TCI states according to scheduling results, and includes theusage configuration information in for example DCI to send to the userequipment k, to indicate interference DMRS configuration in MU-MIMOtransmission to the user equipment k. At the same time, in step S1706,the base station sends information including DMRS configuration of theuser equipment k to the user equipment k via DCI. Subsequently, in stepS1707, the base station transmits downlink data to a group of userequipment including the user equipment k simultaneously on the sametransmission resource. The use equipment k can obtain its DMRSconfiguration and DMRS configuration of other UE in the group bydecoding the received DCI, and demodulates the received data informationaccording to the DMRS configurations.

It should be noted that, the signaling interaction process describedabove with reference to FIG. 17 is only schematic rather thanrestrictive, those skilled in the art may make amendments on theinteraction process according to the principles of the presentdisclosure in conjunction with actual cases. For example, the order ofsteps in FIG. 17 is schematic rather than restrictive. For example, asdescribed above, DCI including usage configuration information of theTCI state is sent in step S1705, and DCI including DMRS configuration ofthe user equipment k is sent in step S1706 respectively, and this isjust to illustrate that the UE k can infer the interference DMRSconfiguration according to the usage configuration information includingthe TCI state without the DMRS configuration of the UE k itself. Inpractice, the two steps may be performed simultaneously. That is, twotypes of information is sent on the same DCI. For example, in order toavoid obscuring the subject of the present disclosure, some interactionprocess less related to the technology of the present disclosure isomitted. In addition, some steps in FIG. 17 may be omitted. For example,in a case that M is less, the activation operation in step S1702 (shownby a dotted line in FIG. 17) may be omitted. All such amendments shallbe regarded to fall within the protection scope of the presentdisclosure, and are not listed one by one here.

According to the third schematic scheme of the present disclosure, DMRSconfiguration corresponding an interference data flow in MU-MIMOtransmission is indirectly indicated to the target user equipment usingthe existing TCI mechanism, so that the user equipment can obtainrelated interference information without significantly increasing aprocess load and signaling overhead, thereby implementing the“non-transparent” MU-MIMO transmission, and thus being beneficial tooptimize the system performance.

(1-4. Fourth Schematic Scheme)

In a fourth schematic scheme of the present disclosure, interferenceDMRS configuration in MU-MIMO transmission group is indirectly informedbased on DMRS configuration of target user equipment and informationrelated to a Code Division Multiplexing (CDM) group in which the DMRSconfiguration is located.

First, related concepts of the DMRS and CDM group are brieflyintroduced. The DMRS consists of an orthogonal sequence of Walsh code(orthogonal code), and a scrambling sequence based on a pseudo randomsequence. In addition, downlink DMRSs (DL-DMRS) for different antennaports are independent, and can be multiplexed in respective resourceblock pairing. DL-DMRSs are orthogonal to each other at antenna ports byusing CDM and/or Frequency Division Multiplexing (FDM). DL-DMRSs arecode division multiplexed with the orthogonal codes in the CDM group.DL-DMRSs are frequency division multiplexed between CDM groups. DL-DMRSsin the same CDM group are mapped to the same resource element. DL-DMRSsin the same CDM group use different orthogonal sequences between theantenna ports, and the orthogonal sequences are orthogonal to eachother. DL-DMRSs for downlink data channel PDSCH can use a part or all ofat most 12 antenna ports (antenna ports 1000 to 1011). That is, in acase of singe user-multiple input multiple output (SU-MIMO)transmission, the PDSCH associated with DL-DMRS can transmit at most 8ranks of MIMO. In a case of MU-MIMO transmission, at most 4 ranks areallocated for each UE, and at most 12 ranks are allocated for all UE.DL-DMRS for the downlink control channel PDCCH uses, for example, a partor all of 4 antenna ports (antenna ports 1007 to 1010). In addition, theDL-DMRS can change the diffusion coding length and the number of mappedresource elements of the CDM according to the number of ranks ofassociated channels.

FIG. 18 is a schematic diagram showing an example of mapping patterns ofDMRS ports 7 to 10 on resource elements (RE). In FIG. 18, shadow filledcells indicate resource elements mapped to the antenna ports 7 to 10(that is, the DMRS ports 7 to 10). Specifically, in LTE, as shown inFIG. 18 for example, DMRS ports 7 and 8 in the same CDM group are mappedto the same resource elements, and thus codeword [+1 +1 +1 +1] andcodeword [+1 −1 +1 −1] are used in a CDM group CDM4. DMRS ports 9 and 10are mapped to the same resource elements, and codeword [+1 +1 +1 +1] andcodeword [+1 −1 +1 −1] are used in the CDM group CDM4.

Generally, in a case that a DMRS port and a CDM group in which the DMRSport is included are determined, other DMRS ports included in the CDMgroup are also determined. In view of this, in the fourth schematicscheme of the present disclosure, the base station may inform the targetUE of usage of all or a part of codewords in a CDM group in which thetarget UE is included via for example DCI, and thus indirectly informsthe target UE of usage of respective DMRS ports in the MU-MIMOtransmission. For example, if in the CDM4, the base station allocatesDMRS port 7 to the target UE via DCI and informs the target UE of a casethat all codewords in the CDM group are used by DMRS ports for MU-MIMOtransmission, the target UE can infer that other DMRS ports 8, 11, 13are interference ports in the MU-MIMO transmission, and thus performsinterference removing and data demodulating to recover a target dataflow, thereby implementing the “non-transparent” MU-MIMO transmission.

Configuration examples at the UE side and the base station side forimplementing the fourth schematic scheme are respectively described indetail hereinafter.

FIG. 19 is a block diagram showing another example of the functionalconfiguration of the device at the UE side according to the firstembodiment of the present disclosure.

As shown in FIG. 19, a device 1900 according to this example may includea determination unit 1902 and a decoding unit 1904. A functionalconfiguration example of the decoding unit 1904 is substantially thesame as the functional configuration example of the decoding unit 304described above with reference to FIG. 3, and details are not repeatedhere.

The determination unit 1902 may include a DMRS configuration setdetermination module 1921 and an interference DMRS configurationdetermination module 1922.

The DMRS configuration set determination module 1921 may be configuredto determine a DMRS configuration set corresponding to a CDM group forMU-MIMO transmission.

Presently, NR supports CDM2, CDM4 and CDM8. After RRC connection isestablished, the base station may notify, for example via UE-specifichigh layer RRC signaling, the target UE of a CDM group in which a DMRSport configured for the target UE is included, that is, which of CDM2,CDM4 and CDM8. In addition, in the RRC layer, if a type of the DMRSconfiguration is determined, a relationship between DMRS and the CDMgroup is also determined. For example, generally, a DMRS associated withPDSCH mainly supports CDM4. In this way, the DMRS configuration setdetermination module 1921 at the UE side can obtain the CDM group forMU-MIMO transmission of a data channel by decoding high layer signalingfrom the base station, and thus uniquely determine a DMRS configurationset corresponding to the CDM group.

The interference DMRS configuration determination module 1922 may beconfigured to determine DMRS configuration of other user equipment asinterference DMRS interference, according to configuration informationon the CDM group included in the control information.

For example, the configuration information on the CDM group may includeinformation indicating whether all codewords are used by the DMRS portsfor MU-MIMO transmission. For example, the configuration information maybe indicated by a bit of information, 1 indicates that all codewords areused, and 0 indicates that a part of codewords are used. Theinterference DMRS configuration determination module 1922 may determineDMRS configuration other than the DMRS configuration of the target UE inthe DMRS configuration set as the interference DMRS configuration, whendetermining that all codewords in the CDM groups are used according tothe configuration information.

In another aspect, if the configuration information indicates that notall codewords in the CDM group are used, it is required to determinecodewords used and codewords not used according to additionalinformation, to determine the interference DMRS configuration.

Preferably, the configuration information on the CDM group included incontrol information from the base station may be information indicatingusage of codewords in the CDM group. The information may be bitmapinformation, preferably. For example, a codewrod occupied by the DMRSport is indicated as 1 in a bitmap, and a codeword not occupied by theDMRS port is indicated as 0 in the bitmap. For example, if bitmapinformation corresponding to the CDM4 is “1010”, it is indicated thatcodewords [+1 +1 +1 +1] and [+1 −1 +1 −1] in the CDM4 are occupied bytwo interference DMRS ports, and two remaining codewords [+1 +1 −1 −1]and [−1 +1 +1 −1] are not occupied.

In this way, the interference DMRS configuration determination module1922 may determine occupied codewords in the CDM group according tobitmap information indicating usage of codewords in the CDM groupincluded in the control information, and thus determine a DMRS portcorresponding the occupied codeword in the DMRS configuration set as theinterference DMRS port.

It can be seen that, the usage of codewords in the CDM group is notifiedby the bitmap, so that the solution according to the present disclosurecan adapt to both the case that a part of the CDM group is used and thecase that the entire CDM group is used. However, in the latter case, asdescribed above, the usage may be indicated by information “1” of 1 bitfor example, thus signaling overhead of the bitmap information can besaved, particularly in the case of CDM4 and CDM8. Therefore, in actualimplementation, the two manners for information notification may becombined. For example, in a case that it is determined that the entireCDM group is used according to information of 1 bit, the interferenceDMRS configuration can be directly inferred according to the DMRSconfiguration of the target UE. In a case that it is determined that apart of the CDM group is used according to information of 1 bit, theinterference DMRS may be determined further based on bitmap informationindicating specific usage of the CDM group.

Corresponding to the configuration example at the UE side, aconfiguration example at the base station side is described hereinafter.

FIG. 20 is a block diagram showing another example of the functionalconfiguration at the base station side according to the first embodimentof the present disclosure.

As shown in FIG. 20, a device 2000 according to this example may includea control information generation unit 2002 and a transmission controlunit 2004. A functional configuration example of the transmissioncontrol unit 2004 is substantially the same as the functionalconfiguration example of the transmission control unit 404 describedabove with reference to FIG. 4. Details are not repeated here.

The control information generation unit 2002 may include a configurationinformation generation module 2021 and a control information generationmodule 2022.

The configuration information generation module 2021 may be configuredto generate configuration information on a CDM group for MU-MIMOtransmission, according to DMRS configurations of a group of userequipment performing MU-MIMO transmission. In a schematicimplementation, the configuration information may be used to indicatewhether an entire DMRS configuration set corresponding to the CDM groupis used for the MU-MIMO transmission, that is, indicating whether allcodewords in the CDM group are used by interference DMRS ports in theMU-MIMO transmission. For example, 1 indicates that all codewords areused, and 0 indicates that a part of codewords are used.

The control information generation module 2022 may be configured togenerate control information by including the configuration informationon the CDM group and DMRS configuration of target UE, to indirectlyindicate the interference DMRS configuration in the MU-MIMOtransmission. The control information may be sent to the target UE viafor example UE-specific DCI of a physical layer. In a case that theconfiguration information in the received control information indicatesthat the entire CDM group is used, the target UE may determine DMRSconfiguration other than DMRS configuration of the target UE in the DMRSconfiguration set corresponding to the CDM group as the interferenceDMRS configuration.

In another aspect, as described above, a part of the codewords in theCDM group may be used. Preferably, in another schematic implementation,the configuration information generated by the configuration informationgeneration module 2021 may include bitmap information indicating usageof the codewrods in the CDM group. For example, 1 indicates that thecodeword is used by the interference DMRS port, and 0 indicates that thecodeword is not used by the DMRS port. The control informationgeneration module 2022 may generate the control information by includingthe configuration information in a bitmap form, and sends the controlinformation to the target UE via for example UE-specific DCI of thephysical layer, to indirectly indicate the interference DMRSconfiguration to the target UE.

In addition, preferably, the device 200 may further include a CDM groupconfiguration unit 2006 configured to configure a CDM group for MU-MIMOtransmission to the target UE.

The CDM group configuration unit 2006 may be configured to, for thetarget UE, generate information indicating the CDM group for MU-MIMOtransmission, to indicate which of CDM2, CDM4 and CDM4 is used. Theindication information may be included in for example high layer RRCsignaling to send to the target UE.

It should be understood that, for different CDM groups (CDM2/4/8), theconfiguration information, for example in the form of bitmap describedabove, indicating the usage of codewords in the CDM group included inthe DCI may have different lengths. Therefore, the base station informsthe user equipment of the used CDM group in advance via RRC, and theuser equipment can interpret bitmap information with different lengthsin the DCI according to the RRC configuration, thereby avoidinginformation demodulation failure.

In addition, it should be noted that, the configuration example at thebase station side described here with reference to FIG. 20 correspondsto the configuration example at the UE side. Therefore, for contents notdescribed here, one may refer to the description at the abovecorresponding position, and details are not repeated here.

In order to further understand the fourth schematic scheme, signalinginteraction process for implementing the fourth schematic scheme isdescribed below with reference to a flowchart shown in FIG. 21. FIG. 21is a flowchart showing signaling interaction process for implementingthe fourth schematic scheme according to the first embodiment of thepresent disclosure.

As shown in FIG. 21, first, after an RRC connection is established, abase station configures a CDM group for MU-MIMO transmission for userequipment k via RRC signaling, in step S2101. Then, in step S2102, thebase station sends downlink reference signal CSI-RS to the userequipment k to obtain channel state information. In step S2103, the userequipment k sends measured channel state information to the basestation. Then, in step S2104, the base station performs MU-MIMOtransmission scheduling based on channel state information reported bythe user equipment k and other user equipment in conjunction with aspecific network state, thus generates configuration informationindicating the CDM group according to a scheduling result, and includesthe configuration information and DMRS configuration of the userequipment k in for example DCI to send to the user equipment k. Theconfiguration information may include information of 1 bit indicatingwhether all codewords in the CDM group are used, and/or bitmapinformation indicating usage of the codewords in the CDM group, toindicate interference DMRS configuration in MU-MIMO transmission to theuser equipment k. Subsequently, in step S2105, the base stationtransmits downlink data to a group of user equipment including the userequipment k simultaneously on the same transmission resource. The userequipment k can obtain its DMRS configuration and DMRS configuration ofother UE in the group by decoding the received DCI, and thus demodulatesthe received data information according to the DMRS configurations.

It should be understood that, the signaling interaction processdescribed above with reference to FIG. 21 is only schematic rather thanrestrictive. Those skilled in the art may make amendments on the abovesignaling interaction process according to the principle of the presentdisclosure further based on actual cases. For example, the order ofsteps in FIG. 21 is schematic rather than restrictive. For example, inorder to avoid obscuring the subject of the present disclosure, someinteraction process less related to the technology of the presentdisclosure is omitted in the above flowchart. All such amendments shallbe regarded to fall in the protection scope of the present disclosure,which are not listed one by one here.

It can be seen that according to the fourth schematic scheme describedabove, the target UE is notified of the DMRS configuration of the targetUE and the usage of the CDM group including the DMRS configuration,according to the determined correspondence of various types between DMRSconfigurations and CDM groups, so that the user equipment obtains therelated interference information without significantly increasing theprocessing load and signaling overhead, to achieve the “non-transparent”MU-MIMO transmission, thereby being beneficial to optimize the systemperformance.

It should be noted here that, according to the first to the fourthschematic scheme, interference condition for MU-MIMO transmission isindirectly informed to the user equipment according to the firstembodiment of the present disclosure, thereby achieving the“non-transparent” MU-MIMO transmission for the downlink data channel. Itshould be understood that, the schematic schemes are preferableimplementations rather than restrictive. Those skilled in the art maymake appropriate amendment or combination on the schemes according tothe principle of the present disclosure, and such variation shall beregarded as falling within the scope of the present disclosure.

[2. MU-MIMO Transmission for Downlink Control Channel (SecondEmbodiment)]

MU-MIMO transmission for downlink control channel according to a secondembodiment of the present disclosure is described hereinafter. TheMU-MIMO transmission for downlink control channel refers to thatdownlink control channels of multiple different user equipment (that is,UE-specific PDCCH) are superposed on the same time and frequencyresource to perform transmission, so as to improve utilizationefficiency of the time and frequency resource.

As described above, in the conventional technology, only a controlchannel for a certain UE (that is, UE-specific PDCCH) is transmitted ata certain time and frequency resource, and control channels for multipleUE are not superposed on the same time and frequency resource to performtransmission as the data channel. The reason is recognized by theinventor as follows. As described in the first embodiment, MU-MIMOtransmission for the data channel of the target UE may be assisted bycontrol signaling (for example UE-specific DCI) carried by the controlchannel UE-specific PDCCH of the target UE. For example, controlinformation related to the MU-MIMO transmission for the data channel(including DMRS configuration of the target UE and information directlyor indirectly indicating the interference DMRS configuration) isincluded in UE-specific DCI. However, if MU-MIMO transmission is alsoperformed for a control channel of the user equipment itself, thecontrol channel cannot be used to provide control information related toits MU-MIMO transmission, that is, DMRS configuration corresponding tothe UE-specific PDCCH of the target UE and optionally DMRS configurationcorresponding to UE-specific PDCCH of other UE. For the above problem,no solution for efficiently achieving the MU-MIMO transmission of thecontrol channel is put forward in the conventional technology.

In the NR system, it is supported to carry information on a time slotstructure by using group common PDCCH (GC-PDCCH), for example slotformat indicator (SFI).

It is required to simply illustrate a relationship between GC-PDCCH andcommon search space (CSS). For CSS, all UE may try to perform blinddecoding, and for UE-specific search space, the UE may try to performblind decoding only in a case that the UE is configured in advance. TheGC-PDCCH in the present disclosure may be located in CSS, and thus iseasily decoded by UE in a group of UE.

In the second embodiment of the present disclosure, control informationrelated to MU-MIMO transmission for the control channel can be carriedby using GC-PDCCH. That is, in the embodiment of the present disclosure,GC-PDCCH includes not only time slot information such as SFI, but alsoincludes control information for controlling MU-MIMO transmission of thecontrol channel. The base station may configure time and frequencyresource available to GC-PDCCH for the user equipment via RRC. The userequipment receives GC-PDCCH by detecting on the corresponding time andfrequency resource, so as to obtain control information related toMU-MIMO transmission for the control channel from GC-PDCCH, and thusrecovers its UE-specific PDCCH from the received superposed signal flowaccording to the control information. The structure for sending GC-PDCCHand UE-specific PDCCH to the user equipment may also be referred to asdual-stage DCI structure. In order to facilitate understanding theprocess, signaling interaction process of the dual-stage DCI structurefor implementing MU-MIMO transmission of the control channel is brieflydescribed with reference to a flowchart shown in FIG. 22.

As shown in FIG. 22, first, in step S2201, the base station sendsdownlink reference signal CSI-RS to user equipment k to obtain channelstate information. The user equipment k sends measured channel stateinformation to the base station in step S2202. Then, in step S2203, thebase station performs MU-MIMO transmission scheduling based on channelstate information reported by the user equipment k and other userequipment in conjunction with a specific network state, and sendsGC-PDCCH (a first stage of DCI) to the user equipment k according to ascheduling result. The GC-PDCCH includes SFI and control informationrelated to MU-MIMO transmission of the control channel. Then, in stepS2204, the base station sends its UE-specific PDCCH (a second stage ofDCI) to the user equipment k. Different from the conventionaltechnology, the UE-specific PDCCH and UE-specific PDCCH of other userequipment in the group for MU-MIMO transmission are superposed on thesame time and frequency resource to perform transmission. Therefore, asignal received by the user equipment includes not only its UE-specificPDCCH, but also includes superposed UE-specific PDCCH of other userequipment. Subsequently, in step S2205, the base station sends a dataflow to the user equipment k, and the data flow and a data flow of otheruser equipment in the group for MU-MIMO transmission are superposed toperform transmission. In this way, the user equipment k recovers itsUE-specific PDCCH from the received superposed signal flow according tocontrol information related to MU-MIMO transmission included in thereceived GC-PDCCH, and then recovers a target data flow from thereceived superposed data flow according to control information relatedto MU-MIMO transmission of the data channel included in UE-specificPDCCH. For the process of demodulating the target data flow according tothe control information related to MU-MIMO transmission of the datachannel included in UE-specific PDCCH, one may refer to the solution inthe first embodiment or other solutions in the conventional technologymay be adopted. Details are not repeated in the second embodiment.

It should be noted here that, in the flowchart shown in FIG. 22, boththe MU-MIMO transmission for the control channel and the MU-MIMOtransmission for the data channel are described, this is only schematicrather than restrictive, and the two types of transmission may beperformed independently. Even if the two types of transmission areperformed simultaneously, the MU-MIMO manner for the control channel maydiffer from the MU-MIMO manner for the data channel. For example, it isassumed that UE-specific PDCCH of one UE includes only one layer inMU-MIMO transmission, and data information of the UE includes multiplelayers in MU-MIMO transmission. Specifically, for example, it is assumedthat three UE performs MU-MIMO transmission, the MU-MIMO transmission ofthe control channel may include only three layers, each layer belongs toone UE; and the MU-MIMO transmission of the data channel may include 6layers, each UE includes two layers of data flow.

In addition, DMRS configuration for transmitting PDCCH (also referred toas PDCCH associated DMRS configuration) may differ from DMRSconfiguration for transmitting PDSCH (also referred to as PDSCHassociated DMRS configuration). For example, the PDCCH associated DMRSis sent with one or more of antenna ports 107 to 114, and the PDSCHassociated DMRS is sent with one or more of antenna ports 7 to 14.

In addition, it should be noted that, the number of layers occupied byUE-specific PDCCH of one UE in MU-MIMO transmission is not limited,which may be one or more. That is, one or more DCIs for one UE may existin one time slot.

Configuration examples of the UE side and the base station side forimplementing schemes of MU-MIMO transmission for the control channel byassisting with GC-PDCCH according to the second embodiment of thepresent disclosure are described in detail below.

FIG. 23 is a block diagram showing an example of functionalconfiguration of a device at a UE side according to the secondembodiment of the present disclosure.

As shown in FIG. 23, a device 2300 according to this example may includeMU-MIMO transmission control information acquisition unit 2302 andspecific transmission control information acquisition unit 2304.

It should be noted that, functional units in the device shown in FIG. 23only represent logic modules divided according to the implementedspecific functions, and are not intended to limit the implementations.In an actual implementation, the functional units and modules may beimplemented as independent physical entities, or may be implemented by asingle entity (for example a processor (CPU or DSP), an integratedcircuit), which also adapts to description of other configurationexamples at the UE side later. Configuration examples of the functionalunits are described in detail in the following.

The MU-MIMO transmission control information acquisition unit 2302 maybe configured to decode for GC-PDCCH of a group of user equipmentincluding target user equipment, to obtain control information relatedto MU-MIMO transmission for control channels of the group of userequipment.

GC-PDCCH from the base station may include control information relatedto MU-MIMO transmission of the group of user equipment where respectiveUE-specific PDCCHs are superposed together. The control information may,for example, include information related to DMRS configurationcorresponding to UE-specific PDCCH of each UE, including a DMRS portnumber, scrambling ID and a layer number or may be information of apseudo random sequence and corresponding orthogonal cover code (CCC) forgenerating DMRS.

The specific transmission control information acquisition unit 2304 maybe configured to decode, according to the acquired control informationon MU-MIMO transmission, UE-specific PDCCH of the target UE which issuperposed with UE-specific PDCCH of other user equipment on the sametransmission resource to perform transmission, to acquire transmissioncontrol information related to the target UE.

PDCCH associated DMRS is sent by using subframes and frequency bands forsending DMRS associated PDCCH. DMRS is used to demodulate DMRSassociated PDCCH. PDCCH is sent by using an antenna port for sendingDMRS. Therefore, similar to the data information, after obtaining atleast DMRS configuration corresponding to UE-specific PDCCH of thetarget UE, the target UE can recover its UE-specific PDCCH from thereceived superposed signal flow, to obtain target UE-specifictransmission control information. The specific transmission controlinformation may be used to perform transmission control on physicaldownlink shared channel (PDSCH) and physical uplink shared channel(PUSCH), and may be also used to perform future transmission control onsidelink, for example, transmission control on sidelink-shared channel(SL-SCH) and physical sidelink control channel (PSCCH). The transmissioncontrol here includes resource allocation, transmissionformat/modulation coding format, hybrid automatic repeat transmissionrequest (HARQ) information, DMRS allocation and so on.

It should be noted here that, the device 2300 at the UE side may beimplemented as a chip or a device. For example, the device 2300 mayfunctions as the UE, and may include an external device such as a memoryand a transceiver (optional, shown by a dotted line block in FIG. 23).The memory may be configured to store program and related datainformation for implementing various functions by the user equipment.The transceiver may include one or more communication interfaces tosupport communication with different devices (for example, a basestation, other user equipment), and the implementation of thetransceiver is not limited, which also adapts to the description ofother configuration example of the UE side described later.

Corresponding to the configuration example of the device at the UE sideshown in FIG. 23, a configuration example of the base station side isfurther provided according to the present disclosure. FIG. 24 is a blockdiagram showing a functional configuration example of the base stationside according to the second embodiment of the present disclosure.

As shown in FIG. 24, a device 2400 according to this example may includea control channel generation unit 2402 and a transmission control unit2404.

Similarly, it should be noted that functional units in the device shownin FIG. 24 only represent logic modules divided according to theimplemented specific functions, and are not intended to limit theimplementations. In an actual implementation, the functional units andmodules may be implemented as independent physical entities, or may beimplemented by a single entity (for example a processor (CPU or DSP), anintegrated circuit), which also adapts to description of otherconfiguration examples at the base station side later. Configurationexamples of the functional units are described in detail in thefollowing.

The control information generation unit 2402 may be configured togenerate group common physical downlink control channel (GC-PDCCH) for agroup of user equipment and UE-specific physical downlink controlchannel (UE-specific PDCCH) for each of the group of user equipment. Inwhich, the GC-PDCCH includes control information related to multipleuser multiple input multiple output (MU-MIMO) for control channels ofall user equipment in the group of user equipment. The controlinformation may include, for example, DMRS configuration correspondingto UE-specific PDCCH of each user equipment.

The transmission control unit 2404 may be configured to send thegenerated GC-PDCCH to the group of user equipment, and control the basestation, based on the control information related to MU-MIMOtransmission for the control channel in GC-PDCCH, to send respectiveUE-specific PDCCH to all user equipment simultaneously on the sametransmission resource.

It should be noted that, the configuration example of the device at thebase station side described here corresponds to the configurationexample of the device at the UE side. For content not described indetail here, one may refer to the description at the above correspondingposition, and details are not repeated here.

In addition, it should be noted that the device 2400 at the base stationside may be implemented as a chip or a device. For example, the device2400 may function as the base station, and may include external devicessuch as a memory, a transceiver (optionally, shown by dotted line blockin FIG. 24). The memory may be configured to store programs to beexecuted to achieve various function by the base station and relateddata information. The transceiver may include one or more communicationinterfaces to support communication with different devices (for examplethe UE, other base station). The implementation of the transceiver isnot limited here. This also adapts to the description of otherconfiguration examples for the base station side later.

In addition to the time slot information such as SFI, GC-PDCCH accordingto the technology of the present disclosure further incudes controlinformation related to MU-MIMO transmission for the control channel.However, as described above, GC-PDCCH relates to all UE, that is, all UEmay try to decode GC-PDCCH. The included MU-MIMO transmission controlinformation relates to only a group of user equipment, for whose controlchannel, MU-MIMO transmission is performed. Therefore, preferably, inorder to avoid decoding to obtain the control information by UE otherthan the group of UE, scrambling is to be performed on the GC-PDCCH. Theconventional DCI scrambling technology is briefly introduced below.

A cyclic redundancy check (CRC) parity bit is added for DCI. The CRCparity bit is scrambled by radio network temporary identifier (RNTI).The RNTI is an identifier which can be specified or set according toobjects of DCI and so on. The RNTI is an identifier pre-specifiedaccording to standard, an identifier set as cell-specific information,an identifier set as terminal device-specific information, or anidentifier set as information specific to a group to which the terminaldevice belongs. For example, during monitoring of PDCCH, the terminaldevice descrambles the CRC parity bit added to the DCI withpredetermined RNTI, to identify whether CRC is correct. In a case thatthe CRC is correct, it can be determined that the DCI is DCI for theterminal device.

In the present disclosure, a group common identifier for specificallyscrambling control information related to MU-MIMO transmission for thecontrol channel in GC-PDCCH is put forward. According to a scramblingobject, the group common identifier may be referred to as MU-PDCCH RNTIor MU-MIMO RNTI, to distinguish from RNTI for other objects. Forexample, an identifier for scrambling SFI in GC-PDCCH may be referred toas SFI RNTI.

In order to further understand the technology of the present disclosure,a relationship between GC-PDCCH and UE-specific PDCCH and informationincluded in GC-PDCCH are described below with reference to FIG. 25. FIG.25 is a schematic diagram showing a schematic structure of GC-PDCCH anda relationship between GC-PDCCH and UE-specific PDCCH according to thesecond embodiment of the present disclosure.

In an example shown in FIG. 25, MU-MIMO transmission of the controlchannel includes four layers. As shown by the right side of FIG. 25,specific transmission control information for four UE is superposed inUE-specific PDCCH received by the UE. From top to bottom, transmissioncontrol information for UE 1, UE 2, UE k and UE m are sequentiallyshown. The left side of FIG. 25 shows group common PDCCH, includinginformation such as SFI and MU-MIMO transmission control informationscrambled with, for example, MU-PDCCH RNTI. Four blocks in the MU-MIMOtransmission control information respectively indicate DMRSconfiguration associated with UE-specific PDCCH of UE 1, UE 2, UE k andUE m (including DMRS port number, scrambling ID and layer number). It isassumed that DMRS configurations corresponding to UE 1, UE 2, UE k andUE m are referred to as DMRS configuration 1, DMRS configuration 2, DMRSconfiguration k and DMRS configuration m. In this case, the UE K may tryto demodulate to recover its transmission control information from thereceived UE-specific PDCCH after obtaining at least its RMRSconfiguration k by decoding GC-PDCCH.

In the following description, as an example, a scrambling scheme forcontrol information related to MU-MIMO transmission of the controlchannel in GC-PDCCH is described in detail in conjunction with a firstschematic scheme, a second schematic scheme and variations of the secondschematic scheme.

(2.1 First Schematic Scheme)

In the first schematic scheme according to the present disclosure, DMRSconfiguration of each UE included in GC-PDCCH is scrambled by usinggroup common identifier MU-PDCCH RNTI. FIG. 26 is a schematic diagramshowing the first schematic scheme according to the second embodiment ofthe present disclosure.

It should be noted that, in the schematic diagram shown in FIG. 26,information such as SFI included in GC-PDCCH is omitted for clarity, andonly parts closely related to the technology of the present disclosureare shown.

As shown in FIG. 26, DMRS configurations of UE 1, UE 2, UE k and UE mincluded in GC-PDCCH are scrambled with MU-PDCCH RNTI respectively.Since the group common identifier MU-PDCCH RNTI is known to a group ofuser equipment performing MU-MIMO transmission (for example, the basestation may configure MU-PDCCH RNTI for user equipment which mayparticipate in MU-MIMO transmission in advance via for example highlayer RRC signaling), UE 1, UE 2, UE k and UE m each may descramble thescrambled GC-PDCCH with the MU-PDCCH RNTI, thereby obtaining four DMRSconfigurations. However, in this case, each UE does not know which DMRSconfiguration is its DMRS configuration or which DMRS configuration isinterference DMRS configuration. Therefore, the user equipment may tryto perform blind decoding on UE-specific PDCCH based on the acquired allDMRS configurations. That is, the user equipment perform differentinterference DMRS configuration assumption to try whether UE-specificPDCCH can be decoded, and verifies information obtained by decoding withUE-specific identifiers (for example, cell radio network temporaryidentifier C-RNTI). That is, the CRC parity bit of the UE-specific PDCCHis descrambled with C-RNTI, to identify whether CRC is correct. If theCRC is correct, the verification is successful, and it is indicated thatthe decoded information is the transmission control information for theuser equipment itself

It may be seen that, in the first schematic scheme, DMRS configurationsof all user equipment in the MU-MIMO transmission group are scrambledwith the group common identifier MU-PDCCH RNTI. This scrambling schememay be referred to as “one stage scrambling scheme”. Each user equipmentmay obtain DMRS configuration of the whole group by decoding GC-PDCCHwith MU-PDCCH RNTI, and decode UE-specific PDCCH by performinginterference removing based on different interference DMRS assumptions.That is, the user equipment knows not only its DMRS configuration, butalso DMRS configuration of the interference UE. Therefore, the firstschematic scheme is equivalent to the “non-transparent” MU-MIMOtransmission of the control channel.

Configuration examples of the UE side and the base station side forimplementing the first schematic scheme are described in detail below.

FIG. 27 is a block diagram showing another example of the functionalconfiguration at the UE side according to the second embodiment of thepresent disclosure.

As shown in FIG. 27, a device 2700 according to this example may includea MU-MIMO transmission control information acquisition unit 2702 and aspecific transmission control information acquisition unit 2704.

The MU-MIMO transmission control information acquisition unit 2702 maybe configured to decode GC-PDCCH from the base station with a groupcommon identifier, to obtain control information related to MU-MIMOtransmission of the control channel. The MU-MIMO transmission controlinformation acquisition unit 2702 may include an identifier acquisitionmodule 2721 and a descrambling module 2722.

The identifier acquisition module 2721 may be configured to acquire agroup common identifier (for example MU-PDCCH RNTI) and UE-specificidentifier (for example C-RNTI) of the UE from the base station. Thedescrambling module 2722 may be configured to decode GC-PDCCH with thegroup common identifier MU-PDCCH RNTI, to obtain control informationrelated to MU-MIMO transmission for the control channel of all userequipment. Taking the configuration shown in FIG. 26 as an example, itis assumed that DMRS configurations corresponding to UE 1, UE 2, UE kand UE m are referred to as DMRS configuration 1, DMRS configuration 2,DMRS configuration k and DMRS configuration m respectively. Taking UE kas an example of the target UE, the descrambling module 2722 of the UE kmay perform decoding to obtain DMRS configuration 1, DMRS configuration2, DMRS configuration k and DMRS configuration m.

The specific transmission control information acquisition unit 2704 maybe configured to decode UE-specific PDCCH of the target user equipment,based on the control information obtained by the MU-MIMO transmissioncontrol information acquisition unit 2702 and the target UE-specificidentifier, to obtain transmission control information related to thetarget UE.

Preferably, the specific transmission control information acquisitionunit 2704 may include a blind decoding module 2741 and a verificationmodule 2742.

The blind decoding module 2741 may be configured to perform blinddecoding on UE-specific PDCCH of the target UE by taking UE-specificPDCCH of other user equipment as interference, based on the controlinformation obtained by the MU-MIMO transmission control informationacquisition unit 2702.

Taking UE k in the example shown in FIG. 26 as an example of the targetUE, the blind decoding module 2741 of the UE k may assume one of theobtained four DMRS configurations (DMRS configuration 1, DMRSconfiguration 2, DMRS configuration k and DMRS configuration m) as itsDMRS configuration, and assume other three DMRS configurations asinterference DMRS configurations, thereby decoding the receivedUE-specific PDCCH by the linear interference removing manner describedabove, for example.

However, it cannot be ensured that the decoded information is thetransmission control information for the UE k. Therefore, verificationis to be performed.

The verification module 2742 may be configured to verify the decodedinformation by using specific identifier (for example C-RNTI) of UE k,and obtain the decoded information which is successfully verified as thetransmission control information for the target user equipment.

The UE k sequentially descrambles CRC parity bits in the decodedtransmission control information by using its C-RNTI, to identifywhether CRC is correct. If the CRC is correct, the verification issuccessful, and it is indicated that this transmission controlinformation is transmission control information for the UE k.

Corresponding to the configuration example at the UE side, aconfiguration example at the base station side is described below. FIG.28 is a block diagram showing another example of the functionalconfiguration of the device at the base station side according to thesecond embodiment of the present disclosure.

As shown in FIG. 28, a device 2800 according to this example may includea control channel generation unit 2802 and a transmission control unit2804. A functional configuration example of the transmission controlunit 2804 is substantially the same as the functional configurationexample of the transmission control unit 2404 described above withreference to FIG. 24. Details are not repeated here.

The control channel generation unit 2802 includes a scrambling module2821 and a notification module 2822.

The scrambling module 2821 may be configured to scramble, by using agroup common identifier (for example MU-PDCCH RNTI), control informationrelated to MU-MIMO transmission for the control channel included inGC-PDCCH, to generate GC-PDCCH.

With reference FIG. 26 above, the scrambling module 2821 scrambles, byusing MU-PDCCH RNTI, four DMRS configurations (including DMRSconfiguration 1, DMRS configuration 2, DMRS configuration k and DMRSconfiguration m) included in GC-PDCCH, to obtain scrambled GC-PDCCH.

The notification module 2822 may be configured to control the basestation to send the group common identifier (for example, MU-PDCCH RNTI)to each user equipment, and thus a group of user equipment performingMU-MIMO transmission for the control channel may decode the receivedGC-PDCCH by using MU-PDCCH RNTI, to obtain DMRS configurations includedin the GC-PDCCH.

It should be noted that, the configuration example of the device at thebase station side described here corresponds to the configurationexample of the device at the UE side described above. Therefore, forcontents not described in detail here, one may refer to the descriptionat the above corresponding position, and details are not repeated here.

It may be seen that, according to the first schematic scramblingsolution, the descrambling operation at the UE side and the scramblingoperation at the base station side each are simple. However, the userequipment is required to perform blind decoding on UE-specific PDCCHbased on multiple interference assumptions, resulting in a greatprocessing load at the UE side. In order to support the user equipmentto perform blind decoding on UE-specific PDCCH, and thus avoid a problemthat a receiver of the user equipment cannot demodulate correspondinginformation since a total layer of MU-MIMO transmission is excessive,preferably, the total layer number may be two or four for MU-MIMOtransmission of the control channel.

In addition, according to the first schematic scrambling solution, theuser equipment can obtain interference condition and performinterference removing and signal demodulation, thereby actuallyimplementing the “non-transparent” MU-MIMO transmission of the controlchannel, and thus improving the throughput and reliability of thesystem.

(2-2. Second Schematic Scheme)

In a second schematic scheme of the present disclosure, a dual stagescrambling scheme is put forward. The dual stage scrambling scheme isdescribed in detail with reference to FIG. 29. FIG. 29 is a schematicdiagram showing a second schematic example according to the secondembodiment of the present disclosure.

As shown in FIG. 29, for DMRS configurations included in GC-PDCCH, twoscrambling processes are performed by utilizing a group commonidentifier and a user specific identifier respectively. Taking UE k asan example, DMRS configuration k included in CG-PDCCH is scrambled byusing the group common identifier MU-PDCCH RNTI and specific identifierof UE k (C-RNTI k) respectively. For example, a first stage ofscrambling may be performed by using MU-PDCCH RNTI first to obtainfirst, scrambled content, and then a second stage of scrambling isperformed on the first content by using C-RNTI k to obtain secondcontent. It should be noted that, an order of the used scrambling RNTIsin the two scrambling processes is not limited. Preferably, scramblingis performed first with C-RNTI k, and then scrambling is performed byusing MU-PDCCH RNTI. Accordingly, the UE k performs descrambling asfollows: determining the occurrence of PDCCH transmission by using thegroup common MU-MIMO RNTI first, and determining its PDCCH participatingMU-MIMO transmission and related information by using C-RNTI k. In thiscase, only the UE k knowing both MU-PDCCH RNTI and C-RNTI k candemodulate DMRS configuration k included in GC-PDCCH. Similarly, each ofother user equipment UE 1, UE 2 and UE m can demodulate only its ownDMRS configuration.

It may be seen that, with the dual stage scrambling scheme according tothe second schematic scheme, the user equipment can obtain only its DMRSconfiguration and cannot obtain interference condition of other UE inthe same group. Therefore, this scheme is equivalent to “transparent”MU-MIMO transmission in essence.

Configuration examples of the UE side and the base station side forimplementing the second schematic scheme are described in detail below.

FIG. 30 is a block diagram showing another example of the functionalconfiguration of the device at the UE side according to the secondembodiment of the present disclosure.

As shown in FIG. 30, a device 3000 according to this example may includea MU-MIMO transmission control channel information acquisition unit 3002and a specific transmission control information acquisition unit 3004.

The MU-MIMO transmission control information acquisition unit 3002 maybe configured to decode GC-PDCCH from the base station by using a groupcommon identifier and a UE-specific identifier, to obtain controlinformation related to MU-MIMO transmission for a control channel of thetarget user equipment.

The MU-MIMO transmission control information acquisition unit 3002 mayinclude an identifier acquisition module 3021, a first descramblingmodule 3022 and a second descrambling module 3023.

The identifier acquisition module 3021 may be configured to acquire thegroup common identifier (for example, MU-PDCCH RNTI) and UE-specificidentifier (for example C-RNTI) from the base station.

The first descrambling module 3022 may be configured to decode thereceived GC-PDCCH by using one of the group common identifier and theUE-specific identifier (for example, MU-PDCCH RNTI), to acquire firstcontent.

The second descrambling module 3023 may be configured to decoded thefirst content obtained by the first descrambling module 3022 by usingthe other of the group common identifier and the UE-specific identifier(for example C-RNTI), to obtain control information related to MU-MIMOtransmission for the control channel of the target UE.

Taking UE k in FIG. 29 as an example, the first descrambling module 3022and the second descrambling module 3023 perform dual stage descramblingby using the group common identifier MU-PDCCH RNTI and specificidentifier of UE k, i.e. C-RNTI k, thereby uniquely obtaining DMRSconfiguration k included in GC-PDCCH. It should be noted that, althoughthe example that the first descrambling module 3022 performs the firststage of descrambling on GC-PDCCH by using the group common identifierMU-PDCCH RNTI first and then the second descrambling module 3023performs the second stage of descrambling by using the UE-specificidentifier C-RNTI is described above, the example is not intended to belimiting. The order of the used descrambling RNTIs in the dual stagescrambling may be exchanged.

The specific transmission control information acquisition unit 3004 maybe configured to decode the received UE-specific PDCCH based on theobtained control information related to MU-MIMO transmission for thecontrol channel of the target UE, thereby obtaining transmission controlinformation for UE k included in the control information.

Taking the UE k in the embodiment shown in FIG. 29 as an example of thetarget UE, the specific transmission control information acquisitionunit 3004 of the UE k may decode the received UE-specific PDCCH based onthe acquired DMRS configuration k of the UE k.

In the schematic scheme, the UE k cannot know DMRS configuration ofother UE in the group, and thus cannot perform interference removing.Therefore, the requirement on the processing performance of a receiverof the UE k is low.

Corresponding to the configuration example at the UE side, aconfiguration example at the base station is described below. FIG. 31 isa block diagram showing another example of the functional configurationof the device at the base station side according to the secondembodiment of the present disclosure.

As shown in FIG. 31, a device 3100 according to this example may includea control channel generation unit 3102 and a transmission control unit3104. A functional configuration example of the transmission controlunit 3104 is substantially the same as the functional configurationexample of the transmission control unit 2404 described above withreference to FIG. 24. Details are not repeated here.

The control channel generation unit 3102 may be configured to scramble,by using a group common identifier and a UE-specific identifier, controlinformation related to MU-MIMO transmission for each UE included inGC-PDCCH, to generate GC-PDCCH, and control a base station to sends thegroup common identifier and a specific identifier of each UE to the UE.The control channel generation unit 3102 may include a first scramblingmodule 3121, a second scrambling module 3122 and a notification module3123.

The first scrambling module 3121 may be configured to, for a group ofuser equipment, scramble control information related to MU-MIMOtransmission for the control channel of each user equipment by using oneof the group common identifier and the specific identifier of each userequipment (for example MU-PDCCH RNTI), to generate first content foreach user equipment.

With reference to the example shown in FIG. 29, the first scramblingmodule 3121 may perform a first stage of scrambling on four DMRSconfigurations (DMRS configuration 1, DMRS configuration 2, DMRSconfiguration k) by using the group common identifier MU-PDCCH RNTIfirst, thereby obtaining first content about UE 1, UE 2, UE k and UE m,respectively.

The second scrambling module 3122 may be configured to scramble firstcontent of each user equipment by using the other of the group commonidentifier and the specific identifier of each user equipment (forexample C-RNTI), thereby generating GC-PDCCH including controlinformation related to MU-MIMO transmission for the control channel of agroup of user equipment.

With reference to the example shown in FIG. 29, the second scramblingmodule 3122 may perform a second stage of scrambling on the firstcontent obtained by the first scrambling module 3121 by using thespecific identifier of each user equipment, for example. Specifically,the second scrambling module 3122 performs, by using C-RNTI 1 of UE 1, asecond stage of scrambling on the DMRS configuration 1 scrambled withMU-PDCCH RNTI, performs, by using C-RNTI 2 of UE 2, a second stage ofscrambling on DMRS configuration 2 scrambled with MU-PDCCH RNTI,performs, by using C-RNTI k of UE k, a second stage of scrambling onDMRS configuration k scrambled with MU-PDCCH RNTI, and performs, byusing C-RNTI m of UE m, a second stage of scrambling on DMRSconfiguration m scrambled with MU-PDCCH RNTI, thereby obtaining GC-PDCCHincluding MU-MIMO transmission control information after dual stagescrambling.

The notification module 3123 may be configured to, for each userequipment, control the base station to send the group common identifierand the UE-specific identifier to the user equipment.

With reference to the example shown in FIG. 29, the notification module3123 sends the group common identifier MU-PDCCH RNTI to the entire groupof user equipment; but sends specific identifier of UE 1, i.e. C-RNTI 1to the UE 1, sends specific identifier of UE 2, i.e. C-RNTI 2 to the UE2, sends specific identifier of UE k, i.e. C-RNTI k to the UE k, andsends specific identifier of UE m, i.e. C-RNTI m to the UE m. In thisway, only the user equipment knowing the two RNTIs can successfullydecodes control information for the user equipment included in GC-PDCCH,thereby decoding the received UE-specific PDCCH superposed with specifictransmission control information of other UE according to the controlinformation, to recover the specific transmission control information ofthe user equipment itself.

It should be noted that the configuration example of the device at thebase station side described here correspond to the configuration exampleof the device at the UE side. Therefore, for content not described indetail here, one may refer to the above corresponding position, anddetails are not repeated here.

It may be seen that, according to the second schematic scramblingscheme, the descrambling operation at the UE side and the scramblingoperation at the base station side are relatively complex. However, eachuser equipment can know only its DMRS configuration, and thus can try todecode UE-specific PDCCH without interference removing. Therefore, areceiver at the UE side can be implemented simply, and thereby theprocessing load is low.

In addition, according to the second schematic scrambling scheme, theuser equipment can demodulate the information according to its DMRSconfiguration without interference removing, thereby actually“transparent” MU-MIMO transmission for the control channel and thussimplifying design of the receiver and reducing the cost.

(2-3. Variation of the Second Schematic Scheme)

According to the second schematic scheme, each UE can recover its DMRSconfiguration only from GC-PDCCH, and cannot know interference conditionof other UE. In the variation, the first embodiment may be combined withthe second embodiment, and thereby the “transparent” MU-MIMOtransmission in the second schematic scheme is converted into the“non-transparent” MU-MIMO transmission.

In a schematic implementation, the total layer number for MU-MIMOtransmission may be included in the control information related toMU-MIMO transmission for the control channel in GC-PDCCH. FIG. 32A is aschematic diagram showing a first example of variations of the secondschematic scheme according to the second embodiment of the presentdisclosure.

Compared with the example shown in FIG. 29, as shown in FIG. 32A, blocksindicating control information for MU-MIMO transmission of UE 1, UE 2,UE k and UE m each include the total layer number for MU-MIMOtransmission, in addition to the DMRS configuration of the correspondingUE.

In the variation, as described in the second schematic scheme accordingto the second embodiment, scrambling is performed on information inblocks corresponding to each UE (including DMRS configuration and thetotal layer number) by using a group common identifier and a specificidentifier, and thus each UE can decode GC-PDCCH to obtain its DMRSconfiguration and the total layer number for MU-MIMO transmission of thecontrol channel. Then, in combination with the first schematic scheme inthe first embodiment, with the DMRS allocation scheme informed to theuser equipment via high layer signaling in advance or the stored defaultDMRS allocation scheme, the user equipment may indirectly infer DMRSconfiguration of other UE which is scheduled simultaneously with theuser equipment to perform MU-MIMO transmission of the control channelaccording to the DMRS allocation scheme, its DMRS configuration and thetotal layer number for MU-MIMO transmission, thereby performinginterference removing and information demodulating, and thusimplementing the “non-transparent” MU-MIMO transmission of the controlchannel. For the process of inferring DMRS configuration of other UEaccording to the DMRS allocation scheme, the total layer number and theDMRS configuration of the user equipment itself, one may refer to thedescription of the first embodiment above, and details are not repeatedhere.

According to the example shown in FIG. 32A, information on the totallayer number of MU-MIMO transmission is set in control information ofMU-MIMO transmission for each UE, and the information is scrambled byusing the group common identifier and the specific identifier of each UErespectively. However, for a group of user equipment performing MU-MIMOtransmission, the information on the total layer number is same.Therefore, preferably, in order to reduce signaling resource occupied bythe information on the total layer number in GC-PDCCH, the informationon the total layer number may be set as information shared by the groupof UE.

FIG. 32B is a schematic diagram showing a second example of variationsof the second schematic scheme according to the second embodiment of thepresent disclosure. As shown in FIG. 32B, the information on the totallayer number is indicated by one block independent from blocksindicating DMRS configurations of four UE. A first stage of scramblingmay be performed on the information of the total layer number with onlythe group common identifier MU-PDCCH RNTI, and thus only the userequipment which is configured with the group common identifier candecode the information on the total layer number from GC-PDCCH.

It should be noted that, the example that interference information inMU-MIMO transmission of the control channel is indirectly inferred basedon the information of the total layer number for MU-MIMO transmission isdescribed with reference to FIG. 32A and FIG. 32B above, but the exampleis not intended to be limiting. Those skilled in the art may makeappropriate modification on the schematic schemes shown in FIG. 32A andFIG. 32B according to the principle of the present disclosure, and suchmodification should be regarded as falling within the scope of thepresent disclosure.

In addition, it should be noted that the example of combination of thefirst embodiment and the second embodiment is described with respect tothe first schematic scheme in the first embodiment and the secondschematic scheme in the second embodiment, but the example is onlyschematic rather than restrictive. Those skilled in the art may makeother appropriate combination on the first embodiment and the secondembodiment according to the principle of the present disclosure, andsuch combination shall be regarded as falling within the scope of thepresent disclosure.

(2-4. Third Schematic Scheme)

Generally, after an RRC connection is established, the base stationconfigures, via RRC signaling, a control resource set (CORESET) in whichGC-PDCCH and UE-specific PDCCH may appear, for the user equipment. Then,the user equipment detects and receive GC-PDCCH and UE-specific PDCCHfrom the base station respectively according to the CORESET configuredby the base station.

FIG. 33 is a schematic diagram showing a relationship between GC-PDCCHand UE-specific PDCCH in a time-frequency domain according to the secondembodiment of the present disclosure.

As shown in FIG. 33, the control channel generally appears on firstthree OFDM symbols, and GC-PDCCH generally appears before UE-specificPDCCH. The base station generally configures a wide range oftime-frequency resources via RRC signaling. With advancement of thecommunication process, the base station will better know resourceallocation and utilization condition of the network, and may expect tonarrow a range of the previously configured CORESET, so as to improvethe resource utilization efficiency.

In addition, it should be noted that, FIG. 33 shows a case where REgroup carrying UE-specific PDCCH includes DMRSs, and the DMRSs andcontrol information for UE-specific PDCCH are placed on different REs inthe same physical resource block (PRB). This differs from the existingcommunication system in which PDCCH does not carry DMRS. Therefore, inthe existing communication system, MU-MIMO transmission cannot beperformed for the control channel.

In view of this, in a third schematic scheme of the present disclosure,indication information of the control resource set in which UE-specificPDCCH may appear may be carried in GC-PDCCH, to narrow the range ofCORESET for UE-specific PDCCH that is previously configured by the basestation via RRC. In this way, resource waste, which is due to failing topredict accurate scheduling information by the base station whenconfiguring the CORESET resource via RRC, can be greatly reduced. Thatis, a search space of the user equipment for UE-specific PDCCH can bedynamically adjusted by using GC-PDCCH, thereby reducing computationcomplexity and power consumption of the UE, reducing a time delay ofdetecting PDCCH, and thus optimizing the system performance and resourceutilization efficiency.

Configuration examples of the UE side and the base station side forimplementing the third schematic scheme are described in detail below.

FIG. 34 is a block diagram showing another example of the functionalconfiguration of the device at the UE side according to the secondembodiment of the present disclosure.

As shown in FIG. 34, a device 3400 according to this example may includea MU-MIMO transmission control information acquisition unit 3402, anindication information acquisition unit 3404, a detection unit 3406 anda specific transmission control information acquisition unit 3408.Functional configuration examples of the MU-MIMO transmissioninformation acquisition unit 3402 and the specific transmission controlinformation acquisition unit 3408 are substantially the same as thefunctional configuration examples of the MU-MIMO transmission controlinformation acquisition unit 2302 and the specific transmission controlinformation acquisition unit 2304 described above with reference to FIG.23. Details are not repeated here.

The indication information acquisition unit 3404 may be configured todecode GC-PDCCH to obtain indication information of a control resourceset to which a transmission resource for transmitting UE-specific PDCCHbelongs.

GC-PDCCH from the base station further includes indication informationof CORESET in which UE-specific PDCCH may appear. Preferably, theindication information may include indication related to OFDM symbolsoccupied by CORESET in which UE-specific PDCCH may appear, that is,indicating which OFDM symbol among first three OFDM symbols on whichUE-specific PDCCH may appear.

The detection unit 3406 may be configured to detect on a correspondingcontrol resource set according to the acquired indication information,to receive UE-specific PDCCH of the user equipment.

Corresponding to the configuration example of the device at the UE sideshown in FIG. 34, a configuration example at the base station side isfurther provided according to the present disclosure. FIG. 35 is a blockdiagram showing another example of the functional configuration of thedevice at the base station side according to the second embodiment ofthe present disclosure.

As shown in FIG. 35, a device 3500 according to this example may includea control channel generation unit 3502 and a transmission control unit3504. A functional configuration example of the transmission controlunit 3504 is substantially the same as the functional configurationexample of the transmission control unit 2404 described above withreference to FIG. 24. Details are not repeated here.

The control channel generation unit 3502 may be configured to includeinformation indicating a control resource set to which transmissionresources of UE-specific PDCCH of each UE belongs in GC-PDCCH, so thateach UE receives and detects respective UE-specific PDCCH by decodingGC-PDCCH.

In addition to control information of MU-MIMO transmission for thecontrol channel of a group of use equipment, the GC-PDCCH from the basestation may further include indication information of CORESET in whichUE-specific PDCCH of each UE may appear. Compared with the time whenconfiguring the CORESET in which GC-PDCCH and UE-specific PDCCH mayappear via RRC, the base station now can perform more accurate resourcescheduling, and thus it can narrow a range of CORESET in whichUE-specific PDCCH may appear, and include related indication informationin GC-PDCCH that appears earlier than UE-specific PDCCH, so that theuser equipment can detect and receive UE-specific PDCCH on the narrowedrange of CORESET according to the indication information included inGC-PDCCH.

Preferably, the indication information may include indication related toOFDM symbols occupied by CORESET to which transmission resources fortransmitting UE-specific PDCCH belong, that is, indicating OFDM symbolson which UE-specific PDCCH may appear.

It may be seen that, according to the third schematic scheme of thepresent disclosure, detailed information of CORESET in which UE-specificPDCCH may appear is included in GC-PDCCH, so that the search space ofthe user equipment for UE-specific PDCCH can be narrowed, for example,narrowed from three OFDM symbols to two OFDM symbols even one OFDMsymbol, thereby greatly reducing the processing load and powerconsumption of the user equipment and reducing a time delay of detectingUE-specific PDCCH. In addition, the base station can perform moreaccurate resource scheduling, thereby greatly improving the resourceutilizing efficiency.

According to the second embodiment, multiple specific implementationschemes for MU-MIMO transmission of the control channel are provided.Compared with the solution in the conventional technology that only acontrol channel for certain UE is transmitted on a certain transmissionresource, the resource utilization is greatly improved according to theschemes shown the second embodiment.

It should be noted that, although the device embodiments of the presentdisclosure are described above with reference to the block diagramsshown in the above drawings, the device embodiments are only schematicrather than restrictive. Those skilled in the art may add, delete,modify, combine and/or change various functional modules according tothe principle of the present disclosure, and all such variations shallbe regarded as falling within the scope of the present disclosure.

[3. Method Embodiments of the Present Disclosure]

(3-1. First Embodiment)

Corresponding to the device embodiments above, method embodiments of thepresent disclosure are provided in the following.

FIG. 36 is a flowchart showing an example of a method at the UE sideaccording to a first embodiment of the present disclosure.

As shown in FIG. 36, the method according to the embodiment starts fromstep S3601. In step S3601, according to control information, which isrelated to MU-MIMO transmission performed by user equipment and otheruser equipment scheduled simultaneously, from a base station,transmission related configuration of the other user equipment isdetermined. The control information include information indirectlyindicating the transmission related configuration of the other userequipment.

Preferably, the transmission related configuration may include DMRSconfiguration. For the process of indirectly inferring DMRSconfiguration of other user equipment by the target user equipmentaccording to information indirectly indicating DMRS configuration ofother user equipment included in the control information, one may referto the description of the device at the UE side in the first to thefourth schematic schemes according to the first embodiment. Details arenot repeated here.

Subsequently, the method proceeds to step S3602. In step S3602, based onthe determined transmission related configuration of the other userequipment, a signal received from the base station and sent by usingMU-MIMO transmission is decoded, to obtain a signal portion for the userequipment.

According to the acquired DMRS configuration of other user equipment,the signal portion of the other user equipment as interference isremoved from the received superposed data flow by the above linearinterference removing manner, to recover the signal portion for targetUE. For the specific process, one may refer to the description of thedevice embodiments at the corresponding position, and details are notrepeated here.

FIG. 37 is a flowchart showing a process of a method for the basestation side according to the first embodiment of the presentdisclosure.

As shown in FIG. 37, the method according to the embodiment starts fromstep S3701. In step S3701, for each of one or more of a group of userequipment which is scheduled simultaneously to perform MU-MIMOtransmission, control information on MU-MIMO transmission is generated,and a base station is controlled to send the control information to theuser equipment. The control information include information indirectlyindicating transmission related configuration of user equipment otherthan the user equipment in the group of user equipment.

The “one or more user equipment” may refer to all or a part of the groupof user equipment. In other words, the base station may indirectlyindicate the transmission related configuration of other user equipmentto a part of user equipment in the group of user equipment, to supporthybrid configuration of “transparent” and “non-transparent” transmissionfor the data channel.

In addition, it should be noted that, for the implementation example ofgenerating control information including information indirectlyindicating the transmission related configuration of other userequipment, one may refer to the description of the device at the basestation side in the first to the fourth schematic scheme according tothe first embodiment. Details are not repeated here.

Subsequently, the method proceeds to step S3702. In step S3702, the basestation is controlled to send a signal simultaneously to the group ofuser equipment on a certain transmission resource.

It should be noted here that, the methods at the UE side and the basestation side in the first embodiment described here respectivelycorrespond to the devices at the UE side and the base station side inthe first embodiment described above. One may refer to the descriptionat the above corresponding position, and details are not repeated here.

(3-2. Second Embodiment)

FIG. 38 is a flowchart showing a process of a method at the UE sideaccording to the second embodiment of the present disclosure.

As shown in FIG. 8, the method according to the embodiment starts fromstep S3801. In step S3801, a group common physical downlink controlchannel (GC-PDCCH) for a group of user equipment including target userequipment is decoded, to obtain control information of MU-MIMOtransmission for a control channel. The MU-MIMO transmission for thecontrol channel here refers to that UE-specific PDCCHs of multiple userequipment are superposed on the same time-frequency resource to performtransmission.

For the implementation example of decoding GC-PDCCH to obtain DMRSconfiguration of all of the group of user equipment or obtain only DMRSconfiguration of the target UE, one may refer to the description of thedevice at the UE side in the first to the third schematic schemesaccording to the second embodiment described above. Details are notrepeated.

Subsequently, the method proceeds to step S3802. In step S3802, based onthe acquired control information of MU-MIMO transmission for the controlchannel, UE-specific PDCCH of the target UE which is superposed withUE-specific PDCCH of other UE on the same time-frequency resource to betransmitted, is decoded, to obtain target UE-specific transmissioncontrol information.

Preferably, GC-PDCCH is decoded to obtain indication information ofCORESET to which transmission resources for transmitting UE-specificPDCCH by the base station belongs, and thus detection is performed on acorresponding time-frequency resource according to the indicationinformation, to receive UE-specific PDCCH.

FIG. 39 is a flowchart showing a process of the method at the basestation side according to the second embodiment of the presentdisclosure.

As shown in FIG. 39, the method according to the embodiment starts fromstep S3901. In step S3901, GC-PDCCH of a group of user equipment andUE-specific PDCCH of each user equipment are generated. Preferably, theGC-PDCCH includes control information of MU-MIMO transmission for thecontrol channel of the group of user equipment. For the specificscrambling process for the control information of MU-MIMO transmissionincluded in GC-PDCCH, one may refer to the description of the device atthe base station side in the first to the third schematic schemesaccording to the second embodiment, and details are not repeated here.

In addition, preferably, GC-PDCCH further includes informationindicating CORESET in which UE-specific PDCCH of each UE may appear, tonarrow a search space of the user equipment for UE-specific PDCCH.

Subsequently, the method proceeds to step S3902. In step S3902, the basestation is controlled to send the generated GC-PDCCH to the group ofuser equipment, and the base station is controlled, based on the controlinformation related to MU-MIMO transmission for the control channel, tosend UE-specific PDCCH of each of the group of user equipment on thesame transmission resource.

It should be noted here, the methods at the UE side and the base stationside in the second embodiment described here respectively correspond tothe device at the UE side and the base station side in second embodimentdescribed above. For content not described in detail here, one may referto the description at the above corresponding position, and details arenot repeated here.

In addition, it should be noted that although the method embodiments ofthe present disclosure are described with reference to the flowchartsshown in FIG. 36 to FIG. 39, the method embodiments are schematic ratherthan restrictive. Those skilled in the art may add, delete, combineand/or change steps according to the principles of the presentdisclosure, and may make appropriate amendments on an order of thesteps. All such variation shall be regarded as falling within the scopeof the present disclosure.

In addition, an electronic device is further provided according to anembodiment of the present disclosure. The electronic device may includea transceiver and one or more processors. The one or more processors maybe configured to perform functions of corresponding units in the methodor device for a wireless communication system according to theembodiment of the present disclosure. The transceiver may carrycorresponding communication functions.

It should be understood that, a machine executable instruction in astorage medium and a program product according to embodiments of thepresent disclosure may be configured to perform the method correspondingto the device embodiments. Therefore, for content not described indetail here, one may refer to the description at the above correspondingposition, and details are not repeated here.

Accordingly, the storage medium for carrying the program productincluding the machine executable instruction is also included in thepresent disclosure. The storage medium includes but not limited to afloppy disk, an optical disk, a magnetic-optical disk, a storage card,and a storage stick and so on.

[4. Computing Device for Implementing Embodiments of the Device and theMethod According to the Present Disclosure]

In addition, it is further to be noted that the above-described seriesof processing and apparatuses may also be implemented by software and/orfirmware. In the case of implementation in software and/or firmware, aprogram constituting the software is installed from a storage medium ora network to a computer with a dedicated hardware structure, e.g., ageneral purpose personal computer 4000 illustrated in FIG. 140, whichcan perform various functions when various programs are installedthereon. FIG. 40 is a block diagram showing an exemplary structure of apersonal computer that can be used as an information processing deviceaccording to an embodiment of the present disclosure.

In FIG. 140, a central processing unit (CPU) 4001 executes variousprocesses according to the program stored in a read only memory (ROM)4002 or the program loaded from the storage section 4008 to a randomaccess memory (RAM) 4003. In the RAM 4003, the data required by CPU 4001to execute various processing is also stored as necessary.

The CPU 4001, the ROM 4002 and the RAM 4003 are connected with eachother via a bus 4004. An input/output interface 4005 is also connectedto the bus 4004.

The following sections are connected to the input/output interface 4005:an input section 4006 including a keyboard, a mouse and the like; anoutput section 4007 including a display such as a cathode ray tube(CRT), a liquid crystal display (LCD) and the like, a loudspeaker, andthe like; a memory section 4008 including a hard disc and the like; anda communication section 4009 including a network interface card such asa LAN card, a modem and the like. The communication section 4009performs communication processing via a network such as the Internet.

A driver 4010 may also be connected to the input/output interface 4005as needed. A removable medium 14011, e.g., a magnetic disk, an opticaldisk, an magneto optical disk, a semiconductor memory, etc., can beinstalled on the driver 4010 as needed so that a computer programfetched therefrom can be installed into the storage section 4008 asneeded.

In the case that the foregoing series of processes are performed insoftware, a program constituting the software is installed from anetwork, e.g., the Internet, or a storage medium, e.g., the removablemedium 4011.

It is to be understood by those skilled in the art that the storagemedium is not limited to the removable medium 4011 shown in FIG. 40 inwhich the program is stored and which is distributed separately from theapparatus so as to provide the program to the user. The removable medium4011, for example, may include a magnetic disk including a Floppy Disk(registered trademark); an optical disk including a Compact Disk ReadOnly Memory (CD-ROM) and a Digital Versatile Disc (DVD); amagneto-optical disk including a MiniDisc (MD) (registered trademark);and a semiconductor memory. Alternatively, the storage medium may be aROM 4002, a hard disk included in the storage section 4008, etc., whichhas a program stored therein and is distributed to the user along withan apparatus in which it is incorporated.

[5. Application Examples of the Technology According to the PresentDisclosure]

The technology of the present disclosure may be applied to variousproducts. For example, a base station described in the presentdisclosure may be realized as gNodeB (gNB), an evolved Node B (eNB) ofany type (such as a macro eNB and a small eNB), a transmission receptionpoint (TRP), enterprise long term evolution (eLTE), eNB and so on. Thesmall eNB may be an eNB such as a pico eNB, a micro eNB and a home(femto) eNB that covers a cell smaller than a macro cell. Alternatively,the base station may also be implemented as a base station of any othertype, such as a NodeB and a base transceiver station (BTS). The basestation may include a main body (that is also referred to as a basestation device) configured to control wireless communication, and one ormore remote radio heads (RRH) disposed in a different place from themain body. In addition, various types of terminals, which will bedescribed below, may each operate as the base station by temporarily orsemi-persistently executing a base station function.

The user equipment described in the present disclosure may be realizedas, a vehicle, a mobile terminal (such as a smartphone, a tabletpersonal computer (PC), a notebook PC, a portable game terminal, aportable/dongle type mobile router, and a digital camera), an in-vehicleterminal (such as a car navigation device), an unmanned aerial vehicle,and a mobile station. The user equipment may also be realized as aterminal (that is also referred to as a machine type communication (MTC)terminal) that performs machine-to-machine (M2M) communication.Furthermore, the user equipment may be a wireless communication module(such as an integrated circuit module including a single die) mounted oneach of the terminals.

Application examples according to the present disclosure are describedbelow with reference to FIGS. 41 to 44.

(5-1. Application Examples of a Base Station)

(First Application Example)

FIG. 41 is a block diagram showing a first example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 1400 includes one or more antennas1410 and a base station device 1420. The base station device 1420 andeach of the antennas 1410 may be connected with each other via an RFcable.

Each of the antennas 1110 includes one or more antenna elements (such asmultiple antenna elements included in a multiple-input multiple-output(MIMO) antenna), and is used for transmitting and receiving a radiosignal by the base station device 1420. The eNB 1400 may include themultiple antennas 1410, as shown in FIG. 41. For example, the multipleantennas 1410 may be compatible with multiple frequency bands used bythe eNB 1400. Although FIG. 41 illustrates an example in which the eNB1400 includes multiple antennas 1410, the eNB 1400 may also include asingle antenna 1410.

The base station device 1420 includes a controller 1421, a memory 1422,a network interface 1423, and a wireless communication interface 1425.

The controller 1421 may be a CPU or a DSP and control various functionsof higher layers of the base station device 1420. For example, thecontroller 1421 generates a data packet based on data in a signalprocessed by the wireless communication interface 1425, and transfersthe generated packet via a network interface 1423. The controller 1421may bundle data from multiple baseband processors to generate bundledpacket, and transfer the generated bundled packet. The controller 1421may have logical functions of performing control such as radio resourcecontrol, radio bearer control, mobility management, admission control,and scheduling. The control may be performed in conjunction with anadjacent eNB or a core network node. The memory 1422 includes RAM andROM, and stores a program that is executed by the controller 1421, andvarious types of control data (such as a terminal list, transmissionpower data, and scheduling data).

The network interface 1423 is a communication interface for connectingthe base station device 11420 to a core network 1424. The controller1421 may communicate with a core network node or another eNB via thenetwork interface 1423. In that case, the eNB 1400 and the core networknode or the other eNB may be connected to each other through a logicalinterface (such as an S1 interface and an X2 interface). The networkinterface 1423 may also be a wired communication interface or a wirelesscommunication interface for radio backhaul. If the network interface1423 is a wireless communication interface, it may use a higherfrequency band for wireless communication than a frequency band used bythe wireless communication interface 1425.

The wireless communication interface 1425 supports any cellularcommunication scheme (such as Long Term Evolution (LTE) andLTE-Advanced), and provides wireless connection to a terminal positionedin a cell of the eNB 1400 via the antenna 1410. The wirelesscommunication interface 1425 may typically include, for example, a baseband (BB) processor 1426 and an RF circuit 1427. The BB processor 1426may perform, for example, coding/decoding, modulation/demodulation andmultiplexing/de-multiplexing, and perform various types of signalprocesses of the layers (for example L1, media access control (MAC),radio link control (RLC) and packet data convergence protocol (PDCP)).Instead of the controller 1421, the BB processor 1426 may have a part orall of the above-described logical functions. The BB processor 1426 maybe a memory that stores the communication control program, or a modulethat includes a processor and related circuitry configured to performthe program. In this way, the function of the BB processor 1426 may bechanged when the programs are updated. The module may be a card or ablade that is inserted into a slot of the base station device 1420.Alternatively, the module may be a chip that is mounted on the card orthe blade. Meanwhile, the RF circuit 1427 may include, for example, afrequency mixer, a filter and an amplifier, and transmit and receive aradio signal via the antenna 1410.

As shown in FIG. 41, the wireless communication interface 1425 mayinclude multiple BB processors 1426. For example, multiple BB processors1426 may be compatible with multiple frequency bands used by the eNB1400. As shown in FIG. 41, the wireless communication interface 1425 mayinclude multiple RF circuits 1427. For example, the multiple RF circuits1427 may be compatible with multiple antenna elements. Although anexample in which the wireless communication interface 1425 includesmultiple BB processors 1426 and multiple RF circuits 1427 is shown inFIG. 41, the wireless communication interface 1425 may also include asingle BB processor 1426 or a single RF circuit 1427.

(Second Application Example)

FIG. 42 is a block diagram showing a second example of a schematicconfiguration of an eNB to which the technology according to the presentdisclosure may be applied. An eNB 1530 includes one or more antennas1540, a base station device 1550 and an RRH 1560. Each antenna 1540 andthe RRH 1560 may be connected to each other via an RF cable. The basestation device 1550 and the RRH 1560 may be connected to each other viaa high-speed line such as a fiber cable.

Each of the antennas 1540 includes one or more antenna elements (such asthe multiple antenna elements included in the MIMO antenna), and is usedfor transmitting and receiving the radio signal by the RRH 1560. Asshown in FIG. 42, the eNB 1530 may include multiple antennas 1540. Forexample, the multiple antennas 1540 may be compatible with multiplefrequency bands used by the eNB 1530. Although an example in which theeNB 1530 includes multiple antennas 1540 is shown in FIG. 42, the eNB1530 may also include a single antenna 1540.

The base station device 1550 includes a controller 1551, a memory 1552,a network interface 1553, a wireless communication interface 1555, and aconnection interface 1557. The controller 1251, the memory 1552, and thenetwork interface 1553 are the same as the controller 1421, the memory1422, and the network interface 1423 described with reference to FIG.41.

The wireless communication interface 1555 supports any cellularcommunication solution (such as LTE and LTE-advanced), and provideswireless communication with a terminal located in a sector correspondingto the RRH 1560 via the RRH 1560 and the antenna 1540. The wirelesscommunication interface 1555 may typically include, for example, a BBprocessor 1556. Other than connecting to an RF circuit 1564 of the RRH1560 via the connection interface 1557, the BB processor 1556 is thesame as the BB processor 1426 described with reference to FIG. 41. Asshow in FIG. 42, the wireless communication interface 1555 may includemultiple BB processors 1556. For example, the multiple BB processors1556 may be compatible with the multiple frequency bands used by the eNB1530. Although FIG. 42 illustrates an example in which the wirelesscommunication interface 1555 includes multiple BB processors 1556, thewireless communication interface 1555 may also include a single BBprocessor 1556.

The connection interface 1557 is an interface for connecting the basestation device 1550 (the wireless communication interface 1555) to theRRH 1560. The connection interface 1557 may also be a communicationmodule for communication in the above-described high-speed line thatconnects the base station device 1550 (the wireless communicationinterface 1555) to the RRH 1560.

The RRH 1560 includes a connection interface 1561 and a wirelesscommunication interface 1563.

The connection interface 1561 is an interface for connecting the RRH1560 (the wireless communication interface 1563) to the base stationdevice 1550. The connection interface 1561 may also be a communicationmodule for the communication in the above high-speed line.

The wireless communication interface 1563 transmits and receives a radiosignal via the antenna 1540. The wireless communication interface 1563may generally include, for example, the RF circuit 1564. The RF circuit1564 may include, for example, a frequency mixer, a filter and anamplifier, and transmit and receive a radio signal via the antenna 1540.The wireless communication interface 1563 may include multiple RFcircuits 1564, as shown in FIG. 42. For example, the multiple RFcircuits 1564 may support multiple antenna elements. Although FIG. 42illustrates the example in which the wireless communication interface1563 includes the multiple RF circuits 1564, the wireless communicationinterface 1563 may also include a single RF circuit 1564.

In the eNB 1400 shown in FIG. 41 and the eNB 1530 shown in FIG. 42, thetransceiver in the device at the base station side may be implemented bythe wireless communication interface 1425 and the wireless communicationinterface 1555 and/or the wireless communication interface 1563. Atleast part of the functions of the device at the base station side mayalso be realized by the controller 1421 and the controller 1551.

(5-2. Application Examples of User Equipment)

(First Application Example)

FIG. 43 is a block diagram showing an example of exemplary configurationof a smartphone 1600 to which the technology of the present disclosuremay be applied. The smart phone 1600 includes a processor 1601, a memory1602, a storage device 1603, an external connection interface 1604, acamera 1606, a sensor 1607, a microphone 1608, an input device 1609, adisplay device 1610, a speaker 1611, a wireless communication interface1612, one or more antenna switches 1615, one or more antennas 1616, abus 1617, a battery 1618 and an auxiliary controller 1619.

The processor 1601 may be, for example, a CPU or a system on chip (SoC),and control functions of an application layer and other layers of thesmart phone 1600. The memory 1602 includes a RAM and a ROM, and stores aprogram that is executed by the processor 1601, and data. The storagedevice 1603 may include a storage medium such as a semiconductor memoryand a hard disk. The external connection interface 1604 is an interfacefor connecting an external device (such as a memory card and a universalserial bus (USB) device) to the smart phone 1600.

The camera 1606 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 1607 may include a group ofsensors such as a measurement sensor, a gyro sensor, a geomagneticsensor, and an acceleration sensor. The microphone 1608 converts soundsthat are inputted to the smart phone 1600 into audio signals. The inputdevice 1609 includes, for example, a touch sensor configured to detecttouch onto a screen of the display device 1610, a keypad, a keyboard, abutton, or a switch, and receive an operation or information inputtedfrom a user. The display device 1610 includes a screen such as a liquidcrystal display (LCD) and an organic light-emitting diode (OLED)display, and displays an output image of the smart phone 1600. Thespeaker 1611 converts audio signals that are outputted from thesmartphone 1600 to sounds.

The wireless communication interface 1612 supports any cellularcommunication scheme (such as LTE and LTE-Advanced), and performswireless communication. The wireless communication interface 1612 maytypically include, for example, a base band (BB) processor 1613 and a RFcircuit 1614. The BB processor 1613 may perform encoding/decoding,modulating/demodulating and multiplexing/demultiplexing, for example,and perform various types of signal processing for wirelesscommunication. The RF circuit 1614 may include a frequency mixer, afilter and an amplifier, for example, and transmit and receive a radiosignal via the antenna 1616. The wireless communication interface 1612may be a chip module having the BB processor 1613 and the RF circuit1614 integrated thereon. The wireless communication interface 1612 mayinclude multiple BB processors 1613 and multiple RF circuits 1614, asshown in FIG. 43. Although FIG. 43 illustrates the example in which thewireless communication interface 1612 includes the multiple BBprocessors 1613 and the multiple RF circuits 1614, the wirelesscommunication interface 1612 may also include a single BB processor 1613or a single RF circuit 1614.

Moreover, in addition to a cellular communication scheme, the wirelesscommunication interface 1612 may also support a wireless communicationscheme of another type, such as a short-distance wireless communicationscheme, a near field communication scheme, and a wireless local areanetwork (LAN) scheme. In this case, the wireless communication interface1612 may include a BB processor 1613 and an RF circuit 1614 for eachwireless communication scheme.

Each of the antenna switches 1615 switches connection destinations ofthe antennas 1616 among multiple circuits (such as circuits fordifferent wireless communication schemes) included in the wirelesscommunication interface 1612.

Each of the antennas 1616 includes one or more antenna elements (such asmultiple antenna elements included in an MIMO antenna), and is used forthe wireless communication interface 1612 to transmit and receive radiosignals. The smartphone 1600 may include the multiple antennas 1616, asshown in FIG. 43. Although FIG. 43 illustrates the example in which thesmartphone 1600 includes the multiple antennas 1616, the smartphone 1600may also include a single antenna 1616.

In addition, the smart phone 1600 may include an antenna 1616 for eachwireless communication scheme. In this case, the antenna switches 1615may be omitted from the configuration of the smart phone 1600.

The bus 1617 connects the processor 1601, the memory 1602, the storagedevice 1603, the external connection interface 1604, the camera 1606,the sensor 1607, the microphone 1608, the input device 1609, the displaydevice 1610, the speaker 1611, the wireless communication interface1612, and the auxiliary controller 1619 to each other. The battery 1618supplies power to each block of the smartphone 1600 shown in FIG. 43 viafeeders which are partially shown by dashed lines in the figure. Theauxiliary controller 1619 operates a minimum necessary function of thesmartphone 1600, for example, in a sleep mode.

In the smartphone 1600 shown in FIG. 43, the transceiver in the deviceat the UE side may be implemented by the wireless communicationinterface 1612. At least a part of the functions of device at the UEside may also be implemented by the processor 1601 or the auxiliarycontroller 1619.

(Second Application Example)

FIG. 44 is a block diagram showing an example of a schematicconfiguration of a car navigation device 1720 to which the technologyaccording to the present disclosure may be applied. The car navigationdevice 1720 includes a processor 1721, a memory 1722, a globalpositioning system (GPS) module 1724, a sensor 1725, a data interface1726, a content player 1727, a storage medium interface 1728, an inputdevice 1729, a display device 1730, a speaker 1731, a wirelesscommunication interface 1733, one or more antenna switches 1736, one ormore antennas 1737, and a battery 1738.

The processor 1721 may be for example the CPU or the SoC, and controlthe navigation function and other functions of the car navigation device1720. The memory 1722 includes a RAM and a ROM, and stores a programthat is executed by the processor 1721 and data.

The GPS module 1724 determines a position (such as latitude, longitude,and altitude) of the car navigation device 1420 by using GPS signalsreceived from a GPS satellite. The sensor 1725 may include a group ofsensors such as a gyroscope sensor, a geomagnetic sensor and an airpressure sensor. The data interface 1726 is connected to, for example,an in-vehicle network 1741 via a terminal that is not shown, andacquires data generated by the vehicle, such as vehicle speed data.

The content player 1727 reproduces content stored in a storage medium(such as a CD and a DVD) that is inserted into the storage mediuminterface 1728. The input device 1729 includes, for example, a touchsensor configured to detect touch on a screen of the display device1730, a button, or a switch, and receives an operation or informationinputted from a user. The display device 1730 includes a screen such asa LCD or an OLED display, and displays an image of the navigationfunction or content that is reproduced. The speaker 1731 outputs soundsof the navigation function or the content that is reproduced.

The wireless communication interface 1733 supports any cellularcommunication scheme (such as LTE and LTE-advanced) and performswireless communication. The wireless communication interface 1733 maytypically include, for example, a BB processor 1734 and an RF circuit1735. The BB processor 1734 may perform encoding/decoding,modulating/demodulating and multiplexing/demultiplexing, for example,and perform various types of signal processing for wirelesscommunication. The RF circuit 1735 may include a mixer, a filter and anamplifier, for example, and transmit and receive a radio signal via theantenna 1737. The wireless communication interface 1733 may also be onechip module that has the BB processor 1734 and the RF circuit 1735integrated thereon. The wireless communication interface 1733 mayinclude multiple BB processors 1734 and multiple RF circuits 1735, asshown in FIG. 44. Although FIG. 44 shows the example in which thewireless communication interface 1733 includes the multiple BBprocessors 1734 and the multiple RF circuits 1735, the wirelesscommunication interface 1733 may also include a single BB processor 1734or a single RF circuit 1735.

In addition to the cellular communication scheme, the wirelesscommunication interface 1733 may also support a wireless communicationscheme of another type, such as a short-distance wireless communicationscheme, a near field communication scheme, and a wireless LAN scheme. Inthis case, the wireless communication interface 1733 may include a BBprocessor 1734 and a RF circuit 1735 for each wireless communicationscheme.

Each of the antenna switches 1736 switches connection destinations ofthe antenna 1737 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 1733.

Each of the antennas 1737 includes one or more antenna elements (such asmultiple antenna elements included in the MIMO antenna), and is used forthe wireless communication interface 1733 to transmit and receive aradio signal. The car navigation device 1720 may include multipleantennas 1737, as shown in FIG. 44. Although FIG. 44 illustrates theexample in which the car navigation device 1720 includes the multipleantennas 1737, the car navigation device 1720 may also include a singleantenna 1737.

Furthermore, the car navigation device 1720 may include the antenna 1737for each wireless communication scheme. In that case, the antennaswitches 1736 may be omitted from the configuration of the carnavigation device 1720.

The battery 1738 supplies power to each block of the car navigationdevice 1720 shown in FIG. 44 via feeders which are partially shown bydashed lines in the figure. The battery 1738 accumulates power suppliedform the vehicle.

In the car navigation device 1720 shown in FIG. 44, the communicationunit in the device at the UE side may be implemented by the wirelesscommunication interface 1733. At least a part of the functions of thedevice at the UE side may also be implemented by the processor 1721.

The technology of the present disclosure may also be implemented as anin-vehicle system (or a vehicle) 1740 including one or more of theblocks of the car navigation device 1720, an in-vehicle network 1741 anda vehicle module 1742. The vehicle module 1742 generates vehicle datasuch as vehicle speed, engine speed, and fault information, and outputsthe generated data to the in-vehicle network 1741.

Preferred embodiments of the disclosure have been described above withreference to the drawings, but the disclosure is not limited to theabove examples of course. Those skilled in the art may make variouschanges and modifications within the scope of the appended claims, andit is to be understood that such changes and modifications naturallyfall within the technical scope of the present disclosure.

For example, multiple functions of one unit in the above embodiment maybe realized by separate devices. Alternatively, multiple functionsimplemented by multiple units in the above embodiments may berespectively implemented by separate devices. Furthermore, one of theabove functions may be implemented by multiple units. Needless to say,such configurations are included in the technical scope of the presentdisclosure.

In the specification, steps described in the flowchart include not onlythe processing performed chronologically, but also the processingperformed in parallel or individually rather than chronologically.Further, even in the steps processed chronically, without saying, theorder may be appropriately changed.

Although the present disclosure and its advantages have been describedin detail, it is to be understood that various changes, substitutionsand alterations may be made without departing from the spirit and scopeof the disclosure as defined by the appended claims. Moreover, the term“include”, “comprise” or any variant thereof in the embodiments of thepresent disclosure is intended to encompass nonexclusive inclusion, sothat a process, a method, an article or a device including a series ofelements includes not only those elements but also other elements thatare not expressively listed or an element) inherent to the process, themethod, the article or the device. The elements defined by the statement“comprising one . . . ” do not exclude that there are other identicalelements in the process, method, article, or device that includes theelements, if not specifically limited otherwise.

1. A device for a user equipment in a wireless communication system, thedevice comprising processing circuitry configured to: obtain, from areceived group common physical downlink control channel (GC-PDCCH),indication information of control resource set in which user equipmentspecific physical downlink control channel (UE-specific PDCCH) appears;and detect the UE-specific PDCCH in the control resource set indicatedby the indication information.
 2. The device according to claim 1,wherein the UE-specific PDCCH and UE-specific PDCCH of other userequipment are superposed on same transmission resource.
 3. The deviceaccording to claim 1, wherein the processing circuitry is configured todecode the GC-PDCCH for a group of user equipment comprising target userequipment to obtain control information related to Multi-User MultipleInput Multiple Output (MU-MIMO) transmission of control channel.
 4. Thedevice according to claim 3, wherein the GC-PDCCH is generated at a basestation by respectively scrambling the control information related toMU-MIMO transmission of control channel of each user equipment in thecontrol information using a group common identifier and a specificidentifier of each user equipment, the group common identifier and thespecific identifier of the target user equipment being transmitted fromthe base station.
 5. The device according to claim 4, wherein the groupcommon identifier is a group common radio network temporary identifier,and the specific identifier is a cell-radio network temporary identifier(C-RNTI).
 6. The device according to claim 4, wherein the controlinformation comprises information related to demodulation referencesignal (DMRS) configuration; and wherein the control informationcomprises a total layer number of the MU-MIMO transmission of controlchannel of the group of user equipment.
 7. The device according to claim1, wherein the indication information comprises indication related toOFDM symbols occupied by the control resource set.
 8. A method in awireless communication system, the method comprising: obtaining, from areceived group common physical downlink control channel (GC-PDCCH),indication information of control resource set in which user equipmentspecific physical downlink control channel (UE-specific PDCCH) appears;and detecting the UE-specific PDCCH in the control resource setindicated by the indication information.
 9. The method according toclaim 8, wherein the UE-specific PDCCH and UE-specific PDCCH of otheruser equipment are superposed on same transmission resource.
 10. Themethod according to claim 8, wherein, further comprising decoding theGC-PDCCH for a group of user equipment comprising target user equipmentto obtain control information related to Multi-User Multiple InputMultiple Output (MU-MIMO) transmission of control channel.
 11. Themethod according to claim 10, wherein the GC-PDCCH is generated at abase station by respectively scrambling the control information relatedto MU-MIMO transmission of control channel of each user equipment in thecontrol information using a group common identifier and a specificidentifier of each user equipment, the group common identifier and thespecific identifier of the target user equipment being transmitted fromthe base station.
 12. The method according to claim 11, wherein thegroup common identifier is a group common radio network temporaryidentifier, and the specific identifier is a cell-radio networktemporary identifier (C-RNTI).
 13. The method according to claim 11,wherein the control information comprises information related todemodulation reference signal (DMRS) configuration; and wherein thecontrol information comprises a total layer number of the MU-MIMOtransmission of control channel of the group of user equipment.
 14. Themethod according to claim 8, wherein the indication informationcomprises indication related to OFDM symbols occupied by the controlresource set.
 15. A non-transitory computer-readable storage mediumincluding computer executable instructions, wherein the instructions,when executed by a wireless communication system, cause the wirelesscommunication system to perform a method, the method comprising:obtaining, from a received group common physical downlink controlchannel (GC-PDCCH), indication information of control resource set inwhich user equipment specific physical downlink control channel(UE-specific PDCCH) appears; and detecting the UE-specific PDCCH in thecontrol resource set indicated by the indication information.